Seems like the internet ad industry wants scale, but doesn't want to solve the problems of scale.
e.g. https://www.asa.org.uk/rulings/person-s--unknown-a23-1198241...
Enforcement is very limited to "misleading ad must not appear again". Eventually they'll have to do something a bit toothier or we're going to have an all-scam internet.
If advertising providers were de jure and de facto liable for fraud, then that will raise the bar for competing advertising providers, as if Google wasn't enough of a monopoly.
Regulation almost universally benefits established players and stifles competition, which is why a lot of regulation is (secretly) backed by large companies. (Note that I'm not saying that regulation never hurts large companies, and regulation can hurt both large companies and small companies/society.)
Such a weird take.. without regulation we would still have child labor, slave labor, cancer causing shit in basically everything, no seatbelts, even worse corruption in politics and companies, .. list goes on ..
We don't have to be on the side of 100% regulation is good but I hope we can see that a lot of regulation is actually making the world we live in liveable.
Really we need some body like the UK ASA to say "you're liable for all these frauds, Google".