I can say with some certainty that the amount of junk mail I get is not significantly lower than in the past, but that’s not addressed to me, usually, it’s almost always “current resident”.

I doubt DMVs are going to move away from accepting mail, but they probably already have an option for your situation, like printing out something from a utility that equates to a bill with your name and address on it.

For proof or residence, it’s usually bill for a utility with your name and address on it. That is to say, you can’t show up with a birthday card sent to your address because anyone can send a birthday card with your name on it to any address, but the cable company, electric company, etc isn’t going to send a bill to your address with your name on it unless you’re on the hook paying that bill.

Is it outdated? Maybe a little. I think paper bills are still pretty normal, even if they’re paid online, but increasingly less so.