I fail to see how e-boks makes this work. Younger people check their e-boks less frequently than average, so sending a physical letter to their address would work just as well if not better.

What makes it work is the public registers.

e-boks sends a text message to the phone, so I see it much faster than a paper mail.

e-boks is like gmail (and others) in that it keeps your old mail. So you can easily find old stuff, a great improvement on paper mail.

I don't even check my physical mailbox once a week.

Denmark is one of the very most digital countries. Physical mail is very much on the way out. We no longer has mailboxes to send mail, you have to go to a shop to send letters, which now cost at last $6 per letter due to the low amount of mail sent.

It is only a matter of less than 10 years before letters will be fully gone.