I live in Denmark, and you can register to not get avertissements in your mail. I must admit I'm surprised it works so well.
That wasn't even what I meant when I wrote we don't get mail. Because it's been about 10 years since we last received an advertisement in the mail. So I completely forgot it's a thing. When you register you also get a sticker, and I can't even recall if that's still on the mail box. 😋
We do get 2 local "free" papers once a week that are paid by advertisements. Those used to be excluded too, but apparently they changed that.
If an advertiser wants to send us mail, they have to send a real letter with name and address, and that today is about 2.5-3 Euro, and requires the advertiser to have that information. I don't recall getting one of those for like maybe 15 years, from a company I used to do business with.
With µblock on my Firefox browser on Linux and Android, and no TV commercials, I live a near 100% advertisement free life. 😀

Junk mail is not a thing outside US. We do get flyers though, but usually sticking a piece of paper on your mailbox saying "no flyers" is enough to never get them.