I.e as a merchant I can easily integrate Apple Pay as an available payment option in the same way as others, but as a customer I can't use Apple Pay unless I'm using Apple sanctioned devices/software and have an Apple account. Other commenters mentioned it only working in Safari, and according to Wikipedia it only works on Apple devices.
Apple Pay is Safari’s implementation of the standard. Apple stores your payment information and uses the Secure Enclave for authorization. How could Apple ensure a secure path on non Apple browsers or on non Apple hardware?
What’s the use case where you would use Apple Pay as opposed to your hardware vendors implementation on a non Apple device?
Just a snippet from the standard.
https://www.w3.org/TR/payment-request/
This specification standardizes an API to allow merchants (i.e. web sites selling physical or digital goods) to utilize one or more payment methods with minimal integration. User agents (e.g., browsers) facilitate the payment flow between merchant and user.
Yeah. It is called the Apple ecosystem. Don't like it? Don't use it. I personally have been very satisfied with Apple so far.
And so you can't use it without being an account holder just like with Mastercard or Visa.