Publishers are responsible & accountable to the FCC and FTC in the United States.
Facebook’s entire argument, until recently, is that they aren’t a publisher.
For TV “The FCC has primary responsibility for determining whether specific advertising is false or misleading, and for taking action against the sponsors of such material.”
https://www.fcc.gov/consumers/guides/complaints-about-broadc...
And the Federal Trade Commission... “When consumers see or hear an advertisement, whether it’s on the Internet, radio or television, or anywhere else, federal law says that ad must be truthful, not misleading, and, when appropriate, backed by scientific evidence.”
https://www.ftc.gov/news-events/media-resources/truth-advert...
The reason we hear about magical cures in spam email & telemarketing is precisely because publishers are held accountable for what they publish & don’t allow those ads in newspapers, magazines, or on TV.