I would suggest the opposite. Perhaps a Facebook doesn't allow this, community. Too much risk of attracting trolls and monsters.

That said. The FBI says that Facebook, Instagram, Twitter et al. They all contain a not insignificant amount of CSAM at any given point in time. The fact just never gets reported by press because they're normalized platforms by the public. Only the fediverse gets that sort of negative attention in the press because it's the disruptive outsider platform. When by both proportion and volume, almost all other platforms have a worse issue with awful content that regularly flies under the radar because they are big corporations.