After which they may or may not continue the practice if the fine is lower than what they’d lose by stopping.

No they're definitely stopping no company can tank 10% of yearly world revenue, every year.

The question isn't whether the fines curb behaviour once imposed, but if they're sufficient deterrence. Dunno whether starting to jail people is actually the best option, easy to get fall guys if you buy them golden parachutes. How about forced share dilution to the benefit of the EU budget: Offend often and hard enough and you'll get right-out expropriated. That's how you hurt shareholders, they all have a joint interest in it not happening (whether small fish or big shark) and I don't think Apple is in the mood to get in trouble with Vanguard Group.

The stock impact is there, but most of it seems to be due to cessation of illegal behaviour (less ROI), not the impact on assets. It's indeed priced in.