In Sweden I saw Swish app QR codes everywhere. In every store, cafe, museums and even for donations (e.g. volunteers maintaining trails, independent museums, etc).
I had no issue paying with a card everywhere, but it was interesting to see those QR codes everywhere.
Though after spending 15min trying to set it up - I eventually made a conclusion that it’s impossible for non Swede (or someone without Swedish bank account and/or mobile phone number). Could be wrong, but did not delve more.
Had to skip couple donations - as they only accepted Swish app.
Heck, paying with card is the default, if you do pay cash, the cashier sometimes has to cancel the card payment before accepting the cash.