You point out some important issues. I encounter this in academia— if each professor trains 5-10 PhD students, where will they go and be professors?
I just want to point out that these systems you mention are all changeable within the larger democratic/market system without a revolution. It might be hard, but lots of things are hard and still get done.
While this "limits of exponential growth" theory sounds plausible, the obvious rebuttal is "When will/did we reach that limit?".
Was there some point in history when each professor only taught one PhD student, or did each professor teach 2 students and the number of universities doubled every 5 years?
Similarly, for how long have the number of lawyers been exponentially growing? Shakespeare wrote "let's kill all the lawyers" in 1591, and fortunately people didn't take that suggestion seriously, so presumably we've had 400 years of exponential growth.
If there was one lawyer in 1591, and it takes 10 years for a junior to become a senior lawyer and start training the next generation, then there should be 2^40 lawyers right now. (That assumes that each lawyer lives forever, so the actual number won't be over one trillion, but still).
I just want to point out that these systems you mention are all changeable within the larger democratic/market system without a revolution. It might be hard, but lots of things are hard and still get done.