So how come epic can sue for stuff like this, but we can’t sue for android to remain open? Is this just a question of having money to fund such a lawsuit?

Unless they completely ditch (or be forced to ditch) the developer notarization crap they’re pushing for, all these talks and “registered appstores” will stay just pure bullshit to distract you from what’s important: https://keepandroidopen.org/

By what about F-droid?