I was going to reply with a whole breakdown of the different technologies at play, but maybe that misses the point. If you change the fundamentals of economics, like say removing any constraints not related to land and natural factors with robots, social structures will change as well. Technology is free enough a big company couldn’t lock it down overnight, you’re right, but that doesn’t necessarily mean the end result is equality, either.

Is the hellscape scenario really that far-fetched? We have inequality and a class system right now, but the average person still moves up or down the socioeconomic ladder somewhat in their lifetime. That’s historically unusual. I hope it doesn’t happen, but hellscape would actually be the least remarkable result to somebody looking back 1000 years from now, in the sense it would match the most of the centuries before.