From my years in academia I have published original reasearch in physics. If I am ever super wealthy I’d love to attempt a similar contribution in another field. I’d probably try for some kind of engineering or anthropology. :)

How are you FI?

> I would really like a job where I can hang around and think and learn interesting stuff about tech and science.

If you achieve financial independence, can't you do that without a job?

Since I was kid I wanted to know many subjects deeply like quantum mechanics, number theory, music, genetics, neurology, robotics, ML and so on. The way I look at PhD is to learn these subjects that I would have anyway but with freedom as well as having someone far more experienced guiding me. This would also help me to identify people who I can collaborate with. Also remember that PhD education is generally free which means it won’t become burden on my financial independence. US and Europe have some great universities at great locations. So I can also satisfy my thirst for travel and getting taste of local cultures. I have little interest in building academic portfolio to get a faculty job. It’s very much learning for the sake of learning. I want to go after big unsolved problems but don’t want to have any pressure. May be some great research might come out of me or may be it won’t. If I was financially independent, I would always be learning something at any point in time and therefore enrolled in some PhD program at any point in time. I might be ending up with may be 4 or 5 PhDs and that had be awesome :).