Uhm, the EU already has free instant SEPA transfers? I use it regularly, sadly not all EU banks support it (smaller ones sometimes have issues and have to resort to standard oldschool 2-day transfer, but they are also free).
It does but there aren't really any SEPA transfer point of sales. It's too asynchronous. You always use card or cash there. SEPA transfer can sometimes be used when paying for things asynchronously online, and they won't ship the item until they receive the money.
SEPA instant transfers aren't guaranteed instant as they might still be withheld for fraud checks.
How do you do your groceries with that?