One of the main or even first rules for a lot of Mastodon is nobody is allowed say anything bad about tansgender or homosexuality an will result in account delete or ban, that much censorship is a cult.
Not allowed to criticize vaccines. I'm not talking about messaging individual users, simply a public posting criticizing trans ideology or injections, banned.
If someone reads the rules across a long list of Mastodon instances, a picture becomes clear about conformity to acceptable speech. Functional healthy adults are mature enough to ignore it or they themself choose to ban a user from messaging them, not an admin who had no part in a conversation. If one person creates multiple account and targets individuals, then yes the admin gets involed.
To prove my point, do a search for a Mastodon instance that allows obnoxious or unpleasant statements, that is still allowed to communicate with more populated instances.
I view the repeated reply of "start your own server" as a cop out to not address what is fundimentally broken about a service, plus it doesn't acknowedge that starting a new instance requires taking on a daily obligation of attending and checking that the service is running and immediately addressing in as short time as possible.
Look at the rules of a instance that focuses on a particular topic or industry, they still have rules for public postings or acceptable speech.
Since Mastodon has the capabilty to ban IP addresses and for one instance to ban another instance from communicating with it, that's using a deny-all rule due to specfic individuals, so everybody on the internet who uses one server do not exist online for people on another server.