That's a bold move. I imagine a lot of businesses will leave Meta over this. And if their gamble pays off, and businesses can't afford not to advertise on Meta platforms, then there is probably a good antitrust case for them abusing their oligopoly power.

There have been many many reasons for businesses to leave Meta over the past decade, and almost none of them have

Doubt it. Most are already being scraped by meta and do nothing about it because they lack the technical competency to even notice it.

Why? Let's say I am a restaurant. How is Meta's activity here damaging to my business?