It's kind of funny that Jack Dorsey sold Twitter to someone who he probably knew might tank the site, only to turn around and rebuild the same thing :)
I guess you can say that the ideas are similar if not identical, with some vital differences: portability of usernames (domains as usernames), federated servers, self-managed algorithms for feeds and based on a protocol (The AT Protocol)
He also funding nostr, so not only one same thing but also twice, both decentralised so elon can't buy them again