Biden's age

A number of people are saying Biden is too old but that is misleading. There are many people his age who are quite active and alert but he is struggling. His problem is not his age but his mental and physical health. He has times when he is lucid and other times he seems lost and these are the early signs of dementia. For some people this can be a long slow decline over many years but on average it takes about two years after initial onset for the person to lose their independence. It is unlikely that Biden could finish a second term with good health. The question is should he be asked to do so.