Because they make more money than they’re paying in fines. They also may be making more money violating laws than they’re paying in fines, but that’s how they’ll have to determine how they conduct business.
Basically - and this is mostly for tech but I suspect it applies to other markets - the US is the single largest market. “Europe” is second, depending on how you want to define it, but even just the EU is a very big market. China is big and growing, and most companies are trying their best to keep growth there. Asia collectively could be huge, but the attempts to collectivize Asia have not worked out well, historically speaking.
But the takeaway is that a company will exit s market if it’s losing money, generally speaking. No one is sacrificing earnings to make sure Belgians have access to the latest phones out of the goodness of their hearts.
The issue is that that’s who Biden and leading members of the democrats are. They do not, in my opinion, have the framework to deal with a political campaign being an existential threat.