DH is 78 and I believe has never exceeded a speed limit. He once misjudged the position of the garage door when reversing the car and bent it a little, but apart from that has never had an accident. He has towed our caravan all over Europe and the UK for nearly 40 years, with outstanding confidence and care. I used to wonder about his ability to react in an emergency until such an occasion occurred about three years ago and his reactions saved our lives and that of the (young) idiot who turned in front of us with no signal or attempt at slowing down.
He isn't very good at reversing these days, takes his time, but is totally safe.
We both have 2-yearly eye tests.
At age 70 he completed the DVLA form and reported that he drank about 20 units a week of alcohol. That said, in the past 40 years he has NEVER EVER driven after having even one drink earlier in the day but since we retired has only driven 2-3 times a week, usually in the daytime. However, this triggered a major rigmarole of medical questions resulting in a refusal to renew his licence until he had had blood tests. For what, we were never told. First of all it took months to be given a list of private doctors who would perform the blood tests - none of them less than 20 miles away, all part-time and with no appointments for months. In fact about half of them had ceased offering the service. Eventually he had the test (costing us £150) and told it could take up to a year to get the results. Meanwhile he could continue to drive. The results came back negative of course, but what a waste of time (and worry and money).
We live in a country village. Taxis are non-existent and public transport is a laugh. We live at the top of a steep hill which neither of us can manage uphill. Being without a car would mean no social life at all as well as problems with shopping, doctors etc. We would have to move without a car.
Of course we would never drive if we considered ourselves to be unsafe.
There are some drivers who have never experienced a motorway, or a single file road, or an emergency stop and I suggest that they are the ones more likely to be a danger on the roads.
We are all different.