As far as I understand it, content posted to one server gets stored on every federated server for the other server's users to see.
This is wrong, else every self hosted instance would've been a storage nightmare.
There have been instances that were defederated for posting nazi / racist content, and CSAM
I assume the later is something CP? Yes, those are legimite cases, just like spam/DdoS, but even then in every case i've seen yet, a Limit would've been enough. A pretty good example seems to be qoto.
I like to emphasize " if both wish to".
If that's included in your view, then what's the point of using a unified protocol? At that point we're more backwards than just using a SSO for everything.
You're probably right on me completely misidentifying the fediverse for what it is, as i expected something like resources shared forums for everyone, but got greeted by admin drama as soon as leaving lemmy for a second. In that sense the fediverse really got a PR issue and users here acting high and mighty to someone not getting their perfect system truly isn't helping it.
Gonna wait for bluesky to play out. ATproto seems a lot more than what i initially expected from activitypub.