Apple Card does offer 2% cash back on all purchases! But only when you pay use an Apple Card via Apple Pay, not when you pay with the physical card. I suspect this is because when Apple Pay is used they have particularly good fraud prevention allowing them to offer this in that case.
Lots of other cards give 2% cash back without Apple Pay and Apple’s advantages in fraud prevention, so I would expect Apple to be able to offer even more cash back if they wanted to attract other credit card users.
