The vast majority of social media content is either:
(1) fake AI-generated content (mostly meaningless crap, avatars, avatar influencers, totally AI-generated long-form posts, and worse) or
(2) unlawful posting of stolen content by users, often aimed at earning ad income, but without permission to republish.
While (1) is the recently added element, the theft and unlawful posting of (2) still accounts for a huge amount of content, although that is often by “innocent” users who conveniently confuse publicly accessible content with content that is public domain.
Beyond things that are fake or unlawful, there’s little of value, but many people choose social media and opt out of the real world, which is still out there, without the fake stuff and stolen goods.