After reading the article this doesn't seem like a good choice for the US. It doesn't even seem very great for Denmark either. The US is vast and has plenty of people who live very remotely compared to Denmark, with the post office as one of the few reliable links to the outside world. There's also people who rely on the USPS for prescriptions which would be seriously hurt if all mail suddenly had a profit motive applied to it.
> There's also people who rely on the USPS for prescriptions
PostNord has stopped delivering letters in Denmark, not everything.