Hear me out.
SomethingAwful forums are notoriously “human,” because they charge $10 for a user account. They don’t have problems with spam/scam/shenanigans that exist on platforms where accounts are free.
Fediverse instances are not currently monetizable - and they should stay that way. But there are still costs to operating one, especially if it’s very popular.
Instance admins charging a minimal fee to register a user account would address both of those concerns, especially the former, especially in light of how the Nicole thing has taken a horribly dark turn.
I think giving people the option to toss some money the way of whoever is hosting their instance is fine. Making it a requirement would kill Lemmy.
Probably not immediately, but the drop in old users coming back and reduction in new users joining would eventually cause it to end up with no users