Apple Pay and Apple Card (for the moment, managed by Goldman Sachs) were the first steps for Apple to join the tremendous remunerative financial market. So many people nowadays use Apple Pay to buy products and services in shops and online.
While technically, such purchases are still a Visa/Mastercard transaction, I believe in the future; it will not be the case anymore. As a result,
$AAPL can soon become a competitor of
$V $MA $AXP.
Apple pay is already accepted mostly everywhere. If you allow people to store money in an Apple account (of course, it will require Apple to own a bank license, but it doesn't look like a problem), you can easily bypass the major credit card circuit.
The first step of it is the rumored Apple Pay Later...
Traditional Banks and the credit card industry will have a serious competitor sooner than later IMO. And I will not be surprised to see a high-profile M&A to seize a bank infrastructure.