Not everyone wants to do that though. There is a lot of extra crap that being a business owner entails. Some people just want to put in their work time and focus on other things. This basically forces everybody devote their lives to entrepreneurship.
We don't need everyone to, though. If AI increases dev productivity X-fold, and this leads to an X-fold increase in entrepreneurship, then the junior devs who want to build someone else's dream will have more opportunities to do so.
... and starve? You know what kind of people create content of their own dreams? Artists. And the stereotype isn't "well-fed artists" for a good reason.
