I occasionally get junk mail addressed to people who haven’t lived in my house in 20 years. I should probably inform the police, just in case they’re drug dealers.
Seriously though, the other side of that coin is that many people have mailing addresses registered in their name but don't get any mail there anymore. Not everyone follows the rules and has only one mailing address. Some people just notify everyone who needs to know, except the Post Office, that they have a new address.
No kidding. Hell, it says in the mailbox block in my townhouse complex that only residents of the townhouse (and you have to leave the postal guy a note saying another last name lives there) receive mail, yet other mail from the previous owner slips through. Hope she wasn’t a drug dealer!