I remember the porn phase of nostr really taking off a few months after Jack started boosting nostr. Relays must be filtering it, because I don't imagine all the bots just gave up. I never see that kind of stuff there now.

But this raises the question: if relays (who I assume don't have billion dollar budgets) can filter it, why can't X?

Answering my own question: X probably doesn't want to filter all porn, just some.