Seems about right.
I think for later adopters though a great target would be to never have less Bitcoin than the miners block reward.
Obviously that number would decrease with the halving every 4 years (could align with people taking profit to improve life quality).
wow, 18 BTC is a lot for me lol
However, I still think that the block reward (~3 BTC) is quite low to think about FIRE or something like that... Anyway, 3 BTC is a lot of money anyway, but far from the "fuck you status"