Anyone saying that people must give up driving at 80 and use buses or taxis is being dogmatic. Obviously, if someone is not fit to drive they should not be driving but that could happen at a younger age or they could be fit to continue for years.
They are also assuming that buses and taxis are readily available - it's similar here, Dizzyribs, so I can sympathise.
Taxis are not available, especially in the evenings and the buses stop in the early evening too. Online shopping is available, as is Amazon etc - but don't mention that on here as others may ask why on earth you don't go shopping in proper shops and that Amazon is the work of the devil. It may be, but it is also very useful if you can't travel far.
Likewise to get to hospital appointments - here we could be sent to any hospital, some of them 35 miles away. Buses? probably have to change two or three times, taking at hours each way.
So what should we do, Dizzyribs? Move to the city where we know no-one? I don't think so!
I hope you can find a supermarket that will do an online delivery. Have you asked your neighbours?