So Google created a chat client (Google Talk) based on XMPP, a federated protocol, and supported the standard until most people were using Google Talk instead of other XMPP clients. They then captured the lions share of XMPP chat usage, stopped caring about keeping up with XMPP developments, defederated and thus killed any interest in others maintaining a decentralized federated protocol for chat.
Years later, Twitter takes a dump on its users and everyone moves to other platforms including Mastodon, a decentralized federated microblogging platform. Meta announces that they are working to become fediverse compatible. The danger is that many people using other platforms including Mastodon will begin using Meta instead, and over time Meta, with the lion's share of fediverse users, will defederate and kill the fediverse.
I'd say I seriously doubt this could happen, but it already has.