Know more than a few, though most made $$$ from some source or another and were able to leave mostly on their terms. Start a coffee shop, or work at their father-in-law's fabrication plant. Pay cut for sure, but they'd already paid off a house and were stable otherwise.

Only one who really jumped in without a plan was a Phd physicist who was teaching in Canada and had enough of academia -- he quit to make cheese full-time. Still doin it.