The code for mastodon, lemmy and kbin is open source and has been forked hundreds of times.
Admins can do whatever they like and people can build and deploy their own instance and enforce their own rules.
This is one of the key strengths of open source, people have forked projects took them in their own direction and had success.
Similarly ActivityPub is documented as a W3 standard, having read the standard the biggest weakness is the number of instances, not the size of the instances.
Also @mod I meant to hit reply and hit report and can't see how to revoke