Ever been to FL or AZ? The oldest people you’ve ever seen are still driving, slowly, dangerously, and happily. No one is taking their licenses with the AARP, around. Meanwhile you may be overestimating the love very old people have for automation, the prospect of being killed by an SDV, or being driven around town by a machine.
The realities of how hard it is for an elderly person to get their license renewed aren't directly relevant here. What matters is the perception of the voters. If they perceive this to be a problem, then someone with money can pay for an ad to play upon those fears and use them to persuade someone to vote against a candidate.
I wasn't talking about whether the law forbids it. There are plenty of people who get too old and frail to drive, and stop driving of their own accord, without the government forcing them to.