Both narratives are just nonsense. The goal of the fines is to change product behavior immediately, and to act as a deterrent for illegal product changes in the future. The fines seem pretty well calibrated for that. $1 billion is real money even to Meta. They can't afford to ignore this and other similar issues, and will need to at least make an effort that looks like good faith enough to avoid the fines ratcheting up higher.
But on the other hand, Meta probably makes on the order of $10 billion / year in profit in the EU. They're not about to leave. Like, even in that one year (2018?) when Google ended up adding a separate line item for EU antitrust fines into their financial statements there was no chance they'd leave.