Biden is 81 years old and seems to be showing signs of the effect of age on us all.
Trump is 78 years old and also seems to be showing some of the same signs. If elected, at the end of his term he would be even older than Biden is currently.
Bogus "cognitive" tests, etc., don't overrule the toll taken by mother nature on every human as time marches on. Not to mention the probability of death as time passes.
Bottom line....both Biden and Trump are too old to execute the duties of Presidency for 4 years, physically and mentally.
Time for younger blood.