> You don't really need to work for a company anymore, because a solo dev can absolutely build crazy things

Don't conflate what is theoretically vs. realistically possible. In the real world, successful companies have moats from data, patents/IP, network effects, and so forth. Just because you can develop something in 1/100th the time doesn't make it instantly feasible to build a new business around. Look around the tech industry today.. plenty of companies that could be disrupted by spry AI-powered buidlers, but they are not (owing to these lock-in effects).