It's less about keeping the existing power hierarchy and more about preventing Apple from forcibly restricting channels or stifling any and all competition.

What if the iPhone 14 was SIM locked to a new Cellular MVNO run by Apple and if you wanted an iPhone you had to sign up for Apple Cellular? The iPhone 14 still used a Qualcomm baseband that supported LTE/5G but Apple locked it down to only their MVNO. An MVNO is a virtual network run on top of an existing network (e.g. AT&T, T-Mobile). How would you feel about that?

Apple NFC uses the same ISO 14443 protocol to talk to Payment Terminals that everyone else uses. Their payments run through the same card processor and merchant account networks as everyone else. There's no reason they couldn't expose the API to allow others to use the NFC capabilities of the iPhone to transact. They just choose not to because it allows them a monopoly.