Is this only for merchants? I feel like here in the US we still don't have a great way to send money back and forth with friends and family. Zelle is decent if both parties' banks support it, but otherwise I've tried Google Pay, Paypal, Venmo, and they all have some problem or another. A lot of them (I'm looking at you PayPal) require you to give them your bank username and password!
If they transact like a credit card processor, there are fees.
This is setup so that you can run an existing merchant app (launching with Stripe) and collect money with all of the same fee requirements as using stripe normally.