Twitter is for shitposting to an audience of scam bots
Cohost is for posting
Tumblr is for looking at the weirdest ads anyone has ever come up with and also a lot of good posts from 10 years ago
Mastodon is for accidentally starting fights with FOSS enthusiasts
I'd just like to interject for a moment. What you're refering to as Mastodon, is in fact, Fediverse/Mastodon, or as I've recently taken to calling it, Fediverse plus Mastodon. Mastodon is not an operating system unto itself, but rather another free component of a fully functioning Fediverse system made useful by the #fediblock blocklist, content warnings for politics, and toots comprising a full social network.
Many computer users run a modified version of the Fediverse system every day, without realizing it. Through a peculiar turn of events, the version of Fediverse which is widely used today is often called Mastodon, and many of its users are not aware that it is basically the Fediverse system, developed by the Fediverse Project.
There really is a Mastodon, and these people are using it, but it is just a part of the system they use. Mastodon is the instance: the server in the network that allocates the users' attention to the latest free software debates. The instance is an essential part of a network, but useless by itself; it can only function in the context of a complete network. Mastodon is normally used in combination with the Fediverse network: the whole system is basically Fediverse with Mastodon added, or Fediverse/Mastodon. All the so-called Mastodon distributions are really distributions of Fediverse/Mastodon!
