I've been twice and I really enjoyed myself.

Tech, finance, and political people definitely don't make up close to the majority. You'd get sort of laughed at if you tried networking earnestly about like tech stocks or LLMs. Generally I don't prefer socializing with techie types from SF, the folks I met at Burning Man were nothing of the sort.

It's mostly just adults who really like dressing up, building stuff, and staying up really late dancing and partying.