As with Hacker News, the existence of a web forum that anyone can create an account on does not imply the lack of a socially and geographically centralized ruling elite.
I would understand "popular".
the people with vast money buy politicians and laws
The main influential people I think of in that crowd who steer the conversations are Eliezer Yudkowsky and Scott Alexander. They're both doing fine financially at this point, I think, but not "buy politicians and laws like Elon Musk" fine.
There are some very rich people who might be loosely associated, like Dario Amodei (maybe?) or perhaps some VCs, but I'm not sure anyone really thinks of them as being a major influence among rationalists, more like people who hopped on the bandwagon. Certainly not ruling it.