> it just doesn't make business sense to put a lot of resources into cleaning up ads that pay google nothing and mostly go to people who temporarily disabled their ad-block

I see where you are coming from, but getting burned by a scam Google advertised to me just pushed me to cutting Google out of my life completely. If it were the occasional bad actor slipping through I might have been more forgiving, but the scam that got to me had become well known for at least the last 18 months. If Google doesn't care enough to keep the well known bad actors off their service, then I protect myself & my family by blocking Google.

Low quality ads should be the bottom of the barrel. Actual criminal activity should not be anywhere in the barrel.