A few days ago I stumbled on another interesting factor which may be useful if people are replaced in simple production jobs.
However, one thing to mention - not all people and even not "most of them" who have taken such jobs are below average, intellectually or else. It's irrelevant to my answer, but I feel the need to mention that.
A lengthy introduction, but eventually I will get to the point of the automation, TL;DR - yes it is super handy and everyone will be busy as bees, without the need to relearn quantum chemistry to be useful for the society, but it might require some changes where to live. I personally would be happy with those changes, some people might be not so excited.
Old times to the present
Since 1.5 million years ago, when people might start to use fire, we did a significant journey.
Most of the time of human history, things we do, amount of work, was directly related to a number of humans we had. They developed tools which improved the amount of work they can do, then domestication of animals happened which was a big improvement. Domesticated animals are equivalent of biological natural intelligence and it was the first thing which significantly multiplied our capabilities, first thing which weakens the link of human as limiting factor in terms of the amount of work which can be done.
Then happened industrial revolution, using steam to amplify our strength even more, and weakening "the human is limiting factor for the amount of work which can be done" even more.
Compared to 300-400 years ago, when most of the humans were in growing food industry, to current days when the participation is about 3% (it differs and the world average is about 27%, which surprised me but will stick with 3%. http://data.worldbank.org/indicator/SL.AGR.EMPL.ZS). So roughly speaking productivity, in some types of actions was improved about 2 orders of magnitude.
However those "free" human resources, aren't free, and they were used to develop other things we have and use now.
Those things are familiar to many, and it is an introduction, not the point of the answer.
We are not so cool, as we might think.
Despite all out progress, since domesticating the fire, we are not so cool today, because we have not enough energy.
Have difficulties to correctly wrap the idea in words, but we do not have an excess of energy. We have enough for our living, but we do not have a significant excess of easily available energy, which we use to do the work for us.
Most rivers we could use to extract energy are already used, and it turned out to be the cheapest source, but not so super for ecology.
Solar in most cases steals potential places for food production, and aren't cheap.
Biofuel also steals food production land.
Windmills installation - aren't cheap, not so reliable (because of wind), not so comfy to live nearby those wind installations when there many of them, they take land too.
Oil and coal and gas - limited resources and there are different ecological disadvantages to extract them, to use them, etc.
Nuclear aren't cheap, is complex and unpleasant if fails, pricey to develop better reactors(molten salt) etc.
All our energy options are compromises and none of them exceeds our expectation in energy production, none of them gives us so much that we do not know what to do with the energy. We need more and we have not enough. Different blackouts are good examples that our demands sometimes exceed our capabilities to produce the energy. We have barely enough energy to do the job, to satisfy our needs.
Light in the tunnel
What does it mean to completely replace humans in production jobs? It means removing the human as the limitation factor for the scale of production. It does not change much in the current situation because energy and matter were limiting factors before and they will be now and as we do not have an excess of energy it will not change our capabilities to produce things and as we do not have cheap options to increase energy production it again does not change price of the goods to supercheap etc.
So basically, there are not many advantages in doing so right now.
However, for the last 60 years, we slowly moving towards the space. And potentially the moving might end our struggle with energy for a lo-o-ong time.
Space is a long story and a lot of factors which should be considered, which I won't do in the answer, keep that in mind while reading.
Annual energy consumption in the world is about 150'000 TWh.
- Moon gets 753 times more from Sun
- Earth as a planet gets 10100 times more
- Sun produces 2.2192×10¹³ times more
Those numbers just a scale of the amount we currently use to what is potentially available.
ITS launch vehicle with expected development cost of \$10 billion and planned payloads 300-550 tons and expected price of delivery 140'000 per ton of payload opens interesting perspectives in terms of expansion in the solar system. (including escaping the planet for \$14000 :D)
One of the interesting aspects of space is that energy extraction in space might be one of the cheapest options available at the moment (when you are in space of course)
And can be done for a price of at least of about 1GJ per kW of production, which is equivalent on earth to about \$27 per kW. For comparison
- building a nuclear plant costs about \$6000 and higher to $18000 per kW of production
- solar panels cost about \$7000-9000 per kW power production
- direct deployment from earth with ITS - \$1400-3000 (10-20 kg per kW of production; delivering solar panels is more efficient, put production them on earth is less efficient)
Absence of atmosphere, 0g or low gravity makes it easier to extract solar energy in a simple and low-tech manner - like this model for the moon installation
source this and this
So when I say it might be equivalent to 1GJ or \$27 it is not just a number, but more or less based on designs and energies required to build those designs. It can be even cheaper than that, using other possible technologies, but it at least can be cheap like that.
The price of increasing of our energy budget is a combination of energy price, labor cost, resources extraction etc. With current prices the process is very slow, so even if you would like to make nuclear reactors or solar panels everywhere - the rate at which those are increasing barely enough to compensate the grow of our population.
Planning to build one power plant takes years, and it takes years to build one after the planning is done. I have another energy-related question and it has some links to prices of building different energy plants, The cost of switching to electric cars? if you are interested about sources, but fastest energy plant to build(2-3 years) are CCGT - combined cycle gas turbines, they use gas to generate energy. The rest is 5-10 years from planning to building.
A space energy extraction is different in that regard, a very different. The limiting factor will be resources, matter to build them, and if the matter is available then you can grow the energy production 10-30 times per year.(with that with that 1GJ per 1kW of production) - this estimation is pretty much conservative and probably it is possible to do better than that.
The difference is actually huge, it is HUGE. If you would like to dedicate all your labor and resources to grow the energy production on earth, using the top art of the technologies, you can't beat steam-like designs in space in terms of speed of increasing the energy you can operate.
Stop at the moment and think about it. Steam era tech in space vs top notch tech on earth. Steam era wins in every aspect - speed of growth, price per kW, the amount of available energy. Stop and think.
- Also, you might watch the video of Isaac Arthur, Industrializing the Moon if you have a question where cheap matter can be extracted for building those space energy plants.
One of the aspects which might make the moon a cheap industrial base for humanity is teleoperating, without the presence of humans on the moon itself. And it does not seem like a super complex job and looks more like a game, to mine vaspen gas etc. Ability to remove a human from production process will play very well with such base, it is almost the requirements to do so.
Ability to vastly increase energy production and do it fast, and ability to remove humans from the production opens another niche of decision making. To monitor that potentially huge complex of production. Decision making on a level of a strategy game. No matter good we are or could be at managing those facilities of that automation production, but if the production complex would be 1000 times bigger than current as an example then even simple monitoring (watch for the red light) and simple decision-making process like this section has red light so it needs to be replaced if it is not an error of the monitoring system which has to be determined, will require some labor. If it is million times bigger than today? If it is billion times bigger than today? If it is trillion times bigger? I do not ask for the answer if it is 2.2192×10¹³ times bigger.
When the amount of the available energy can grow like 10-30 times per year and each year it is not a stretch to have million, trillion bigger production complexes in space compared to our current production lines and factories.
Considering not only the perspective of possible future automation but also other factors which we are planning to do in the near future, full automation of production is not a curse which raises different social and financial problem, but a blessing which supplements those future events we are expecting or doing at the moment. I mean access to space in the first place, but it might(or not) be thermonuclear energy sources as an example, but space is most important because it gives us the space to expand.
You should understand that even if we would be able to transfer energy from the space with an efficiency of 0.1% it can benefit people on Earth and can replace all current energy production (if it is less harmful to ecology). Because 1GW of production initially launched with the ITS, as an example could reach global earth energy production in about 3 years, and in another 2 years reach the capability to replace all that earth energy production even with 0.1% transfer efficiency.
The production allows making other projects which would make the Earth a better place - more food, regulated climate, etc. Really big projects which benefit all the human on earth, even if they do not leave the earth.
There are a lot of possible implications and incentive to do such projects.
So, as for the question of pros and cons - there are only pros in there. Because the possibility to use and the huge field of implication will require full involvement of all humans even with full production automation.
Almost have forgotten about the part which excites me personally.
Moving from earth into space habitats.
Moving from Earth is energy expensive process and it requires a lot of energy, about 7GJ per human with a small backpack.
Having enormous production facilities and energy sources in space allows to build space habitats and move people for the earth into space and from space to the earth. It really opens the new era of our history. So welcome automation where is possible, we need it so much and the future where we need it is very very close.