I don't think you understand how it works.
E: For those of you who don't understand how the fediverse works, it's a distributed network of servers. I can host 100 users on a potato. Vested interests like Vivaldi can host 6300 users. Non-profit platforms like Mastodon can host a few million. Not that hard to match Meta's infrastructure when the resources required per individual are so much less, and is distributed across so much more.