That's an option, but there are a lot of downsides to being a professor, in addition to upsides. It's not at all a clean alternative to being an independent researcher; you're an employee expected to play a certain kind of game (which involves things other than scientific merit, like status/PR, grant funding, publication-counting, etc.).

But in any case, my main point was that you're incorrect that not spending money means sitting around on a beach doing nothing.