@filippo Moving to non-Mastodon software can break a federation as well where you might be lost completely.
I have the same misunderstanding in the design of Mastodon.
Why don't they support resolving the instance by DNS? It would give a chance to have a mastodon instance outside of the main domain. I don't want to expose an ActivityPub data on the main domain, the domain is not related to my Social Media.
Having a unique domain/subdomain for Mastodon makes no sense at all as well. The idea of having domain is to have many underlying services there. We don't need to create unique domains for:
- website
- XMPP
- Email
- etc.
It should be one domain with all those identity services behind it.
It would also give a simpler change to have multiple identities on the same instance. Just like email.
We'd pay some subscription to a public instance (that already have all of those caches/huge db/etc.), with our domains.
As a result, you don't own infra, but you own your identity. If you want to migrate, just switch to another instance (obviously subscribers and posts might require some process).
Most importantly, it would not cost any more for mastodon.social, for instance, to give you a chance to point your domain's identity there.
You should not self-host it, it's too expensive for small batch of users (due to caches, reading history, media, etc.