What's the definition of a "political ad"?
Its obvious if it is say "vote for Trump" or "vote for Harris". If it is pro abortion rights in the US most could infer which candidate it supports but even if you'd argue that's not certain it is obviously political in nature. What about an ad supporting green energy? One could argue that's political, but the motivation behind the advertising might be to encourage consumers to buy solar panels.
So I don't think Google saying "we won't accept political ads" is going to get them off the hook. Some of those who want to run political ads are going to try to sneak them by, and some will succeed. What's Google say then, "well they didn't tell us it was political how we were to know?"
I don't know anything about the law so maybe Google is bs'ing when they say the law is unworkable and that's why they are dropping political ads, but if that's true and it is equally unworkable to drop political ads because you'll still get in trouble, it could be a case of damned if you do and damned if you don't.