One example is flee markets, or different type of second hand. Christmas markets etc. Some do accept debit / credit cards but a lot is swish only.

For cards, depends on the bank. I know my bank at-least do send the card abroad to my current home and as long as i keep my digital authenticator ID (bank ID) i am able to access that, renew cards. Do most banking services etc.

I also managed to get a new bank authenticator by going to the embassy and get signed papers etc, however it took about 5 months or so if you don't have any cash that might become a issue. :)

Lots of smaller cafes or people running various stall style businesses only accept Swish, especially out the in more rural areas. I've been to a couple of smaller festivals where the only way to pay for a ticket at the 'door' was with Swish.

Plus of course any time you need to give money to an actual person and not a business.

Good luck getting a debit card without an address.