@Gargron
For all those new people coming:
I'm so happy to see you arrive.
Know that Mastodon is a distributed network that, nowadays, has over 2800 independent servers. You are free to choose a server/node/instance depending on your criteria or even settle your own.

At the same time, Mastodon is part of a larger federation which includes other distributed social networks: Friendica, Pleroma, PeerTube, Hubzilla, etc. This means that socialmedia is now in the hands of people and not corporations.

For further information:
the-federation.info/