I have known the forum for a while, and it is very frequent to see many legendary activities. It can be seen that they spend a lot of time and energy to maintain the normal operation of the forum, and of course many legendary members are not staff. So I feel like they're all doing bitcoin full time. In fact, working in the decentralized financial field is a new form of work, which may be fully reflected in various DAO organizations in the future and will be rewarded accordingly. Many people will also say: You bought Bitcoin, put it there, forget about it, you dont need to work. It sounds ridiculous.
Those legendary rank users that you are talking about aren't working fulltime on "bitcoin". They are just engaging in discussion and perhaps learning something new everything. They aren't getting paid by bitcointalk or anyone. They are just normal users like us. The operation of the forum is maintained by administrators and the "staff/moderators". As far as I know they do it voluntarily and gets paid a little from the advertisement revenues (not sure about this). The only way some users earn is by renting out their signature space to advertise for different projects/games, but none of them will pay you enough to make it a fulltime "work".