Because those companies chose to operate in the EU. Regulating its market is one of its main tasks, and certainly not a waste of time. That depends on the perspective. From the perspective of a company abusing its market dominance, it is indeed a pain. For the perspective of companies which are not dominant and consumers, it is really desirable for the EU to be active in this field.

Hey, do you know that the EU also have the power to ban companies from doing business in the EU ? That's because like every market, it's a regulated market.

EU is very pro business but, unfortunately for Apple, they are the one writing the rules.

Apple feels really arrogant trying to get around the rules of EU while also accepting every regulation with their tails between their legs in China.

I have a lot of Apple products, I really like them, but EU can get along without their products, so if they want to sell on this continent, they have to follow the rules.

They're global companies, not American ones. EU consumers lose out by Apple's decision. If you want to trade in Europe you've gotta pay by the antitrust rulebook.

By that logic Bayer should not get sued for RoundUp in America because it's an German company :D A bit silly

Basically, when non-EU companies operate within EU, they have to follow EU's rules and regulations. EU might suspect something that goes against those.

Epic and Apple are doing business in the EU, American companies don't have extraterritorial rights here.

Why is the US at times poking its nose into European businesses? On both cases (EU or US): because 1) they can, and 2) they think it is related to their remit.

Because what these two American companies are doing affects a lot of EU citizens.

There are several Apple stores within easy driving distance of me in the UK. Clearly Apple has to obey UK, and European law. You don't get to ignore laws you don't like, just because you are based in another country.