I’ve been waiting 15 years for Facebook to die

That is a lot of hate not only for Facebook but Social Network. 15 years ago would be 2007. For a lot people that may still be MySpace or Friendster.

facebook's comment spam problem seems to be worse than ever, and simultaneously, google's search result spam problem seems to be worse than ever. Both are massive turn-offs.

(paraphrasing) "i was right and it only saved users by buying instagram" != "first ever user shrinkage on facebook"

which alternative is better? why?

not going to happen anytime soon. keep waiting.