Twitter X had one of the biggest L's in SEO history. 3 billion clicks a month from Google. 5 billion clicks a month from Google.
Part of the reason for this could be due to how Twitter migrated to X. Backlinks are a cornerstone of SEO. They're what gives websites authority in the eyes of Google.
When Twitter migrated to X, the devs did it in the wrong way so that Twitter's backlinks were not transferred over. They used a 302 temporary redirect for Twitter to X instead of a 301 permanent redirect. The permanent redirect transfers all the backlinks.
The 302 redirect, since it's only supposed to be used for temporary scenarios, does not transfer backlinks, and X is still using it. A 302 temporary redirect, which means they have to rebuild all the backlink authority that Twitter gained in its 17 years of operating. If you manage a website, you don't want to end up like this because.