How do kids get pocket money in Sweden? I can't imagine grandparents handing over prepaid debit cards to 8 years old to go buy candy at the neighborhood store?
Swish is the de facto standard for sending money between individuals [2], and that's what grandparents tend to use to send money to their grandchildren. It's fee-less (for person-to-person transfers use at least) and it connects your bank account with your phone number. So if anyone wants to send you money, they can just open Swish and enter your phone number (or scan a QR code) and send you some. You also have to sign the payment with the BankID app, which is the de facto standard for authentication [3].
And when I write de facto standard I really mean it. 99.9% of Swedish residents age 18-67 have BankID (8.6M users), while Swish has 8.7M private users (93% of which use Swish at least once per month).
[1] https://www.swedbank.se/privat/kort/bankkort/bankkort-master...
Doing this in a digital system requires first some computing device (be it phone or laptop or whatever) then check the account value, read it correctly, then do some arithmetics and then interpret the result. That's a year or two older.
When counting money is just arithmetics and never cash, something is missing, and it's very clear in many young kids. Money is just points in a game, suddenly you're out, and then you can't get what you want anymore.