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.