Does no one own the companies?
The whole modern society and capitalism exist on assumption of meritocracy: an entrepreneur takes the risks and provides the organization and gets the reward. If there is some perfect machine that always brings profits, there is no risk. Everybody can make such "organization" saying "/goal make me money". The current model also assumes that if you learn and work hard enough, then you get a success of some level. That assumption of the meritocracy also breaks.
If there is no organizational work, nor risks, nor meritocracy, nor "fair reward for hard work" the whole model fades. There are might be different rational choices. One is probably to liquidate the owners of the companies; nationalize the model's output and distribute the profits, for example. Still many questions about everyday life for completely jobless society will arrive then. It might be something else, but people generally do what they see fair, and they also want to eat something.
Ownership is a fragile idea, Russian Empire shows that pretty clearly. It exists only when most of the society agrees that the ownership is fair or when you have enough force to maintain it against those who don't, which is not the case when the majority is on the other side.
Your strongest point is “will people stand for a world with no jobs, where only a percentage of the population owns most things?” And the answer is who knows, people stand for a massive amount of inequality right now, and technology for suppressing the masses is getting much better every year. It’s a big unknown imo, and probably contingent on too many things to predict at all.