Considering the stranglehold that huge platforms have on users, it makes a lot of sense for organizations to have their own fediverse servers, with communities and access they control.
For example, a lot of governments use Twitter as a way to communicate in disaster situations. But since Elon lets anyone with a credit card have a check mark and bans people on a whim you can't trust that the account is a real one or that it won't be cut off in time of need. A Mastodon server would solve both of these problems.