I agree with a lot that you say and notice similar trends in our work. I am a little skeptical about this one though:

"You don't really need to work for a company anymore, because a solo dev can absolutely build crazy things, so it's not like you need to rely on anyone else."

One of the reasons for devs to work in company is not that they can't deliver the work themselves. It's that they don't have the connections to land customers. Most devs need a company at least to handle the marketing so they can focus on what they are good at.

Not only that, but do you really want to be handling the contract negotiations, sales, business taxes, insurance, and everything else?

Being a sole-proprietorship means doing things you aren't skilled in and, most likely, not interested in doing. When I did it, I had a horrid work-life balance and I would not recommend it.

Also, I don't think LLMs have invented a way to make our applications maintenance-free. At some point outages become very costly, and a 24/7 support schedule for 1 dev is going to have trouble scaling. When production is down, we generally don't have some frontline staff vibecode it back up.