> If Google, MS, etc. had ever gotten together and developed a way to filter malicious ads out of their own ad services

This is the crux of it.

If they can't block scammers from their own platform then they should be fined out of having the platform in the first place. The profit they make should easily cover it - unless they like profiting from promoting scams, in which case they should be fined out of having the platform in the first place.