No, that's not what people did back in the day. Those who managed lived off advances from their publishers, inheritance, sponsors, or Church sinecures. It's not possible nowadays. You need to promote your works and it became much less socially acceptable.

It's a weird observation that going off the grid would price you out of the dating market. Plenty of "starving artists" and outright bums have more success with women than salarymen.

And again, what fraction of people who stop working in the for-profit economy will actually be as productive as Joey Hess?

That's the direct counterargument to most BI hopes. Of course, it's very difficult to verify empirically and mostly depends on what you already believe about human nature. We don't even know if Joey Hess is more or less productive than he would be otherwise.