I'm not sure I understand Stripe's value proposition here. What is the benefit of using Stripe's library over using ApplePay (PassKit) directly? (Honest question)
You can't use Apple Pay directly: you have to use it with a supported payment platform. (List is at https://developer.apple.com/apple-pay/. )
"The alternative is to provide your own server-side solution to receive payments from your app, decrypt payment tokens and interface with the payment provider. Handling credit and debit card payments can be complicated and unless you already have the expertise and systems in place, an SDK from a payment provider is the quickest and most reliable way to support Apple Pay in your app."
From: https://developer.apple.com/apple-pay/Getting-Started-with-A...