Both Biden and Trump should be summarily dismissed from office on age infirmity grounds.
Retirement age ought to apply as much to politicians as to workingmen, moreso in fact; as soon as you turn 70 years of age, you should automatically be barred from office, except lesser advisory positions.
Political office today is an extremely demanding post, which you need to be a nearly supremely capable, energetic and mentally focused individual to hold in a way that respects the needs and interests of an electorate that puts its trust in you.