Unless you’re wild camping, campsites have addresses. So do marinas where a ship would need to be docked more or less regularly to establish residency.

As for being a nomad, you don’t need a driver’s license or any kind of ID to wander if you’re willing to sleep rough. If you want to drive on public roadways though, you better have a primary address where the courts can send someone if you kill someone in a traffic accident and bail.

Docking is expensive, so no. It's also only needed once per 5 years or so for maintenance.

Government fining you a ticket doesn't mean your address has to be on the drivers license. They could register the number plate to an SSN for instance.

For most situations where you don't have a permanent address, your address is either the place where you receive mail or the courthouse.

And if you don't have a place to receive mail?

Receiving mail is a requirement for participating in the legal system, which is a requirement for citizens.

Laws of the government can't override laws of physics. If you don't have a place where you can receive mail, do they just arrest you or what?

In some places in the U.S. it is (or at least was until recently) illegal to be healthy and unemployed.