You forgot to mention UX. SEPA payments have horrible user experience. The "modern" way of receiving money in automated manner in Europe and using SEPA is through payment providers. On checkout, customers get redirected to payment providers with strange startup names they've never heard about to initiate a transaction, and then redirected to their bank to log in and approve the initiated transaction. This is basically training people to accept phishing and MITM attacks.

Checkout via Paypal or debit/credit cards is much more straightforward and user-friendly, which is why they are still widely used (along with local services like Swish). A crypto wallet app that just requires scanning a QR code is even better, and miles ahead of anything SEPA/PSD2 offers in terms of user experience.