The infrastructure trap.
You have a society. Together, you build a brighter future! 20% of the society's output is dedicated to an awesome bit of infrastructure for 10 years. In the end, we get a shiny new bit of infrastructure -- an aqueduct, a road, a robot workforce.
Everyone rejoices. The standard of living grows! The rich get richer. The poor get richer. Everyone gets richer! Now, maybe the poor get 10% richer, and the rich get 100% richer. But everyone gets richer.
Now this infrastructure ages. Really, it needs to be completely rebuilt every 30 years (or maintained at the cost of rebuilding it); you need to repair things, replace things, and upgrade the robots. But in the first 10 years, there is very little need to do any of this.
After 10 years, problems start developing. So you claw back on the wealth of everyone. The poor are now 5% richer and the rich are 95% richer than they used to be.
After 10 more years, you are even further behind on your rebuilding your infrastructure. Now the poor are no better off than before you build the shiny new infrastructure, and the rich are now 90% better.
No more! Say the rich. No more taxes!
10 more years and you fall behind even further on rebuilding it. It is now shoddy and falling apart. The poor are now 5% worse off than if you never built it, and the rich are 80% better off. All of this investment has managed to extend the lifetime of the infrastructure by 10 years
10 more years pass, and now the infrastructure is in shambles. The rich don't want to go back to how poor they where before the infrastructure was built. The middle classes are squeezed. And the poor, they are really badly off; there is no more blood to be taken from squeezing them.
Replacing those obsolete robots/leaking aqueduct/pothole filled roads would require a huge investment by people who are already making a pile of money, and mainly benefit the poor and middle classes. The people with power are busy making their next fortune in QM and Medicine, or funding raids to bring home slaves, or investing in farmland, and have no time for pedestrian "update labor robots to newer standards". They have plenty of service workers who can do that!
Strange, however, that they keep on having problems getting enough educated talent locally. Oh well, I guess we can offshore it.