I do not see why a Driver's License as ID is necessary when State ID exists. To drive, you essentially need a bunch of irrelevant documents that have no bearing on driving. Bundling up features has a cost. How many people have state ID honestly? Why would state ID be necessary if you have a Passport or even Trusted Traveler Cards which are Federal ID?
Why isn't a driver's license like a pilot's license? Y'know, where it only has authority on the instrument you are using. I wouldn't be surprised if driver's license as ID is connected to voting because it is really dumb as shit. Who knows, maybe decentralized id will be needed for voting and driver's license will incorporate it in 100 years. Hah.