Coming at it from a different perspective, I did something similar to this by saving money on a US salary and then moving to a low cost of living country. I spent years at a time not working or even thinking about how to make money. I think almost everyone has felt the pain of financial and social obligation, but very few people have experience a total lack of such obligations for years at a time which leads to things like fantasizing about FU money.
I can tell you that for me personally I don't think it was ideal. Yes, at first the freedom is exhilarating, but it doesn't last forever. There were two big problems. One is that you feel disconnected from society. This is hard to explain but being outside of normal social structures you lose a sense of context and meaning to your actions. Second is that when you don't have any social or financial pressures it's hard to avoid the path of least resistance. It's very easy to fall into bad habits, just watching youtube, reading reddit, bad diet, etc.
I would assess myself as someone who would be less susceptible to these problems. I consider myself a fairly self-motivated person and definitely an introvert. But after several years it starts to weigh on you.
Today I work in an office. There are often times when it's hard and I have to deal with things I don't want to. But I still think it's better than when I wasn't working. I think if I never had the experience of not working I would probably only see the downsides of office life as the upside is quite abstract and hard for me to articulate. I don't think this is something unique to me, I think it's human nature to want social structure and this naturally comes with social obligations. But for most people not being constrained to social structures was never an option anyway so they underestimate how much it affects their happiness.