Can someone help me understand how it is different from the traditional schemes like ACH and SEPA? Or is the built on top of these existing rails to make the payment?
From a consumer POV is there a preference for open banking tools like Plaid or Trustly while shopping online?
ACH & SEPA are payments rails, which facilitate the interbank transfer of money. So for example, the app you have given permissions to make transfers to will request a transfer through the open banking APIs to your bank, then the bank itself will use the payments rails to process the transfer.