In the end, I do know several third party candidates that had a lot of trouble posting genuine ads... so there's a bit of a problem all around.
It's worked pretty well for discriminatory housing ads.
With political ads? What is the crime being committed? If it is fraud, then we make it illegal to place an ad without rendering your ID, like with a bank account.
Even for tech companies, that exemption is limited; Craigslist got an exemption, but Roommates.com didn't because of the level to which its platform actively encouraged discriminating on prohibited categories.
Facebook is even now being pursued by HUD over its own tools allowing housing ads to be targeted by race, gender, ZIP code, or disability. https://www.npr.org/2018/08/19/640002304/hud-hits-facebook-f...
The financial industry as well as many others say hi.
I'm sorry, we make people show ID to buy cigarettes and beer - mass political advertising needs SOME sort of regulation.
Lying, in and of itself, is not illegal. While that may be unfortunate, that is also true. So to speak :)
And don't forget, the OP is responding to GP proposing simply banning political ads on Facebook altogether, not simply fraudulent ones.