My question is more science-based than hard sci-fi. Basically, I'm envisioning a scenario in which technology is advanced enough that life has spread through the solar system, and this mostly via self-replicating artificial intelligence.
There are all sorts of practical reasons why humans would avoid trying to build structures on, say, Mercury, because of the harsh conditions. I was considering, however, that isn't the planet a massive source of heavy metal material while also being open to easily collecting solar power? I'm envisioning AI structures keeping mostly under ground and in shelter. Gravity and atmosphere are not as much a concern as for biological life, but smart machines using drones to mine and fabricate what they need, while being able to easily collect direct solar power during the bright days.
Also, wouldn't fabricating system-traversing ships via AI be practical on Mercury due to the availability of energy, material, and lesser gravity [pull] to escape from?
EDIT [2019-12-25] ::
So many great answers. You guys have really given me fully-conceived theories that blow my mind. I cannot expound fully in comments below, so I'm putting this up here.
I'm conceiving of some world building of nearly self-realized robots which are fabricating essentially what they need and taking the time to do it. I chose Mercury and not Venus because the enormously thick atmosphere on Venus keeps the temperature so high (and doesn't cool down much at night) that it would be an obstacle (destructive, corrosive) for my robots.
Whereas, on Mercury, it planet is smaller and the the gravity penalty is also light. But I'm also envisioning that having some gravity is useful to AI bodies, as they still benefit from the simple functions of heat rising from endothermic reactions, and having lose and scattered material (from construction and mining) also continually falling back down to the ground. I'm also factoring that light planetary gravity would be useful for some basic hydraulic systems operating with gravity. (With liquid hydrogen stored in underground pools, perhaps?) The lack of much atmosphere means practically negligible pressure/friction/wind to interfere with operations, including ejecting craft into space travel via railgun.
I'm also curious about the placement of Mercury and its proximity to solar winds, and as to whether that would make mining/collecting solar elements any easier. (I guess 'close" to the sun is extremely relative. I want to incorporate hydrogen mining, but I'm fully aware I may need to do some hand-waving to make that a story point.)