Earlier quoted context omitted.
The primary cited reason for the cashless trend is the ability for shops to simply say no. Anti-money laundry laws trickle down from EU level.
And the most obvious reason for the cashless trend is that cashless is easier and more fruitful for buyer and seller. Buyer just touches their card/phone to the machine. Who likes dealing with cash? (Answer: Germans)
Edit: Please comment if things are different in your non-Swedish country (considering Europe here, but curious about other countries of course).