https://www.dps.texas.gov/section/driver-license/drivers-age...
https://www.dmv.com/md/maryland/senior-drivers?tg1=DVA&utm_c...
Florida has vision requirements, and accepts reports of medical issues making driving unsafe: https://www.flhsmv.gov/driver-licenses-id-cards/medical-revi...
In that context Florida’s standards are lax, but still exist.
Luckily she basically never drives anyway [edit: because my dad who's still a decent driver drivers her around when she needs it because they both know she's not safe on the road, not because she can get by without a car], but I doubt that was an isolated incident. Because of how we've designed our cities, not being able to drive can represent a huge loss of freedom. In the moment, it seems some (and I'm guessing many) DMV workers take pity on the vulnerable elderly person in front of them rather than some hypothetical future victim of that driver.
I feel like if driver licensing required re-certification, everyone would hate that, but it would have the added value of making sure to reinforce that people knew what the law _was_. Maybe it'd be less painful if our insurance already subsidized the cost. I feel bad even advocating for such a thing.
Or perhaps since laws have changed or new laws were made that you were unaware of (through no fault of your own - these things are hard to keep track of!). I agree people would hate it, but I think there's value in, like you say giving people a refresher about the law.
I also think there's value in reminding people that driving is not an inalienable right and also inviting a person to re-evaluate their situation every so often to think if they still really need a car.