I have friends in their 40s who retired early. And most of them are loosing their minds. It's sad and frustrating to watch. They have nothing much to focus on daily, and after a few years of it, you can see the cognitive decline compared to the rest of the peer group. Their people skills keep degenerating, from lack of constant challenges that the middle aged adult deals with at work or home. And that mounts over time, making lot of things harder and harder.
I get all the frustrations people (rightly) have with institutions, govt and corporate robot wonderland, but I have done more interesting and personally satisfying things being within those structures, than I have done anything outside them.
Financial independence is not just an emergency eject button when faced with difficult choices. It a big asset in the corporate world while competing with a cohort that is deep in debt (alimony/kids college/health expense/mortgages/golf club membership etc etc). Sooner or later everyone in any org knows who can be bought and who can't. Both kind of people have value to the org and impact on the org. People who misunderstand that, end up pushing the eject button prematurely.