For starters there is going to be percentage commission on each payment instead of just a flat fee low price like iDeal has. For some reason they felt compelled to introduce buyer protection like a credit card has, instead of just making it a digital debit payment system. And now we are also forced in to the Google ecosystem.
Great. Just great.
Why do they even feel they need the Google Play integrity API anyway? If you are really so concerned about the kind of attacks that supposedly fixes, you better ban Windows, macOS and Linux desktops and notebooks from banking online. Because their security model doesn't even come close to what Android or iOS has.