facebook isn't going to implement detection though. Many (if not most) of the viral pictures are AI-generated. and facebook is incentivized to let their users get fooled to generate endless scrolling

Along with those being fooled there are many comments saying this is fake, AI trash and etc. That portion of the commenters are teaching the ignorant and soon no one will believe what they see on the Internet as real.

They already did. Certainly on the backend. For a while they were surfacing it, but I think it's gone again. But Meta is definitely onto this.