Whenever safe driving is being discussed this is one of the questions that crops up. Too young? Too old? Rather like the question of whether men or women are the better drivers!
Having lived in Florida (sometimes called God's Waiting Room) for some years and seen people in their 90s still driving, I do know that there has to be a definite cut-off point. For example, it was a 98-year-old who made an illegal left turn (equivalent of a right turn in the UK) across in front of me. Fortunately I was slowing down expecting the lights to change. I smashed his front passenger door but there weren't any personal injuries. Just my lovely, lovely car written off due to a cracked chassis. The Highway Patrol officer kept the other driver's licence!
I know people in their 80s who are still capable drivers but I would still question their doing long distance driving. Let's be honest, the older we get the less stamina we have.
I am in my mid 70s, have loved driving and in my youth participated in motor sports but I have now given up driving. A couple of years ago I became aware that my reactions had slowed down and my concentration sometimes wasn't all that it should be. Then I found that every time I drove long distances my eyes started watering and blurred my vision. Not good so no more long distance driving.
When I realised six months after the MOT that I had only driven 300 miles I decided I no longer need a car. (The money saved goes a long way towards a holiday!).
I am fortunate enough to have a High Street with proper shops, can order heavy and bulky grocery items online and have them delivered and have a very reliable and frequent bus service.
I know that not everyone is that lucky, but for people living in or on the edge of towns there are taxis. Work it out, if you only use your car once or twice a week to go to the supermarket a taxi is probably cheaper than running a car.