Apple‘s revenue share of mobile app/game downloads is estimated to be about
70% of the global market.
Numbers for Apple Pay‘s share of mobile wallet transactions are harder to come by (accurately), but has been given as
more than 90% in the U.S. Most probably lower in the EU. Yet even in Germany, the most populous EU country and an Android-leaning market, surveys show it
on par with Google Pay as the most popular service by far.
So yes, they
are a dominant player in mobile.
They haven’t. You’re obviously ill-informed how credit cards work.
Mastercard and VISA operate payment networks - but they
do not issue cards to consumers and
they aren‘t setting interest rates. They‘re merely licensing their brand and providing access to their networks. It’s the individual bank or credit card issuer (say, BoA, Capital One, Barclays, HSBC) that issued your card that sets their interest rates - and bears the risk of consumers failing on payments.
And yes, interest rates for credit cards are set in a
competitive market. Again, that’s the point of EU regulation: To open up these devices to enable competition- and have a dominant player such as Apple charge competitive prices.