American who has lived in Germany here. I would say this:

SEPA transfers are way better than checks for any transaction requiring either.

SEPA and credit card are about equal for things like rent payments and the like (if there aren’t additional CC fees to pay like you see in rents typically).

For most consumer purchases I.e. in a store or online, credit card is miles ahead in simplicity. There’s a reason almost every other country except Germany uses cards almost exclusively now. It’s convenient not having to carry around change.

In short, the best system is one with SEPA and CCs in my book. Pretty sure the Nordics have that setup, or at least Denmark.