The real issue is that so many of these elderly people really believe (and probably correctly) that their lives will effectively be over if they can't drive. And that's because their life to date, their neighbourhood and our whole society is built entirely around driving.
If our towns and suburbs were better equipped for walking, wheeling, cycling and getting about by means other than the car, people wouldn't suddenly get to a point where they can't drive anymore and therefore can no longer participate in society. Nobody should HAVE to drive to live.
My aunt initially thought this when her eyesight started to go, 20 years ago. But she got past it and managed perfectly fine with buses and taxis. I realise it wouldn't work for everyone but probably a greater proportion than would be expected.
She's pushing 90 now and struggles with breathlessness and mobility, but still travels to see us by train from the W coast to Edinburgh