Perhaps what is eventually needed is some sort of Fediverse Alliance that operates under established usage/ethical guidelines.

To join the Alliance, an instance must sign a Terms of Agreement/Charter/Constitution that is written (and owned w/ potential for future amendment) by said alliance. It would contain all of the data usage rules and operational ethics that must be adhered to in order to be a member of the Alliance (and therefore have access/be joined to the group of allied Fediverse instances via federation).

If such an Alliance were successfully formed (especially if top-instances banded together) it becomes a powerful mechanism to filter out the bad and protect the users. For example: perhaps one charter rule is no for-profits or corporate instances?

If an instance violates the charter they would face defederation from the Alliance—perhaps by vote? ( ie group level defederation). At this point the offending instance(s) could of course create their own Alliance. However the benefits of being in the “Primary Alliance” are lost (or gained!).

Just thinking out loud.

Edit: Alliance self-governance would need to be thought of very very carefully in order to protect against corruption and hostile acts….