I could give $5 billion to my FAANG right now and I bet we'd still be breached (hell, I'm pretty sure we already have that budget in my FAANG's security department). The US DoD already has a cyber security budget of $10 billion, and they still get breached.
You underestimate the amount that these companies care about security. Just because they get fined "only" a couple hundred million dollars doesn't mean they aren't scared shitless by being breached. I've sat in boardrooms with CEOs telling us they were willing to pay whatever it takes to increase their security (and they put their money where their mouth is, too). They still get breached.
Budget isn't everything. Does it help? Sure. Like any other security professional, I can recount plenty of tales of teams deprioritizing security in favor of something else. Would they have done differently if they were incentivized better by bigger potential fines? Maybe. Would they have actually been able to implement ironclad security even if they did prioritize it? In the cases I've seen, it's doubtful.
edit: and consider this. If you truly do think that money is everything, you should realize that you will never be able to throw more money at your security than a nation state attacker like China will be able to throw at breaching your security. In the competition of who can spend the most money, you've already lost.