Yeah, that’s a bit of a problem in general. But in this case we’re talking about Meta. It’s one thing, if $randomCompany from outside the EU does it. As long as they’re not doing business within the EU and not specifically target the EU as a market, then they might try to get the company and fine them and may or may not succeed.
Meta on the other hand provides service explicitly for EU citizens & companies. Not only did they localize Facebook, Instagram,… for European languages, they offer the service to sell ads for European companies. In this case, the EU can and will have a way to get them fined, I they want.