so, my question is, is it possible to make full transaction success without backend server/stripe?
You can process a transaction on your client side app using the Apple Pay native iOS SDK, along with the built in Apple Pay service. All of this can be done without a server side component or integration with another vendor. Now, at some point you will need to integrate with a Payment Processor, whether that is Stripe or another vendor, that is completely up to you. However, sending the payment token to the Payment Processor is something that needs to be done because this is how the transaction is processed and how funds are ultimately exchanged. For a list of available Payment Processors, please see this page.
Matt Eaton
DTS Engineering, CoreOS
meaton3@apple.com