Fraud or specifically false advertisement is not protected by the First Amendment. 15 USC 52 and ff.
> What's the compelling interest in this case that allows the government to control speech?
Ghost job postings negatively impact interstate commerce.
Sure, people wasting time applying to ghost jobs has a societal and economic cost, but what is the impact of government regulation of freely advertising job postings?
How does that stack up against the compliance cost of ensuring all of these regulations are being met so the company aren't fined, and the loss of legitimate postings to all of the places they would normally be posted to due to those regulatory cost?
The government has no business to be restricting speech in this manner.
This might suck for companies but sadly their peers made it necessary. Corporations keep telling us they will do the bare minimum of good behavior required by law and instead focus solely on return. Don't be surprised that we are now adjusting to that now that previous norms have been thrown out.