The minimum age requirement was intended to provide a safeguard against the election of individuals who might lack the maturity and experience needed for such a significant role.
The maximum age is a different consideration.
The maximum age is a different consideration.
while it is very much possible that an aged individual is mentally proficient.
That doesn’t mean no 80 year old is more mentally proficient than the average 60 year old, but we want more than average here.
So, no, decline is fully independent from state, just like a derivative, a trend, does not determine a value. There exist GDP growth of 15%/yr: they do not indicate a big GDP.
Robert F. Kennedy Jr., Trump, and Biden are all showing significant issues and they aren’t getting better over the next 4 years.
Nobody has greatly declined and is still among the best choices. I’d happily set the same standard at say 75-80 for Congress and Judges here, but Presidents need to be able to quickly deal with complex and novel issues. That’s exactly the kind of problems where age has the biggest impact.
Would that occasionally reject some still capable people? Yes, but there’s over 330 million people in the US, we can pre filter and still have plenty of options.
So the end result of those age requirements is that you prevent people from getting the necessary experience to become good leaders, resulting in way older politicians than most countries. Politicians being too young isn't an issue anywhere, politicians too old however...
An old person may have accumulated tremendous valuable experience in their field but it is increasingly hard to start over in a new field.
This is even before our mind and health decays and some of us get to walk the earth as shadows of our former self.
Also, there is no required experience or competence. There should be but there isn't. Aging to 35 helps very little.
...and Biden will be 82 at the end of his term.
Trump would be ~6 months older than Biden in 4 years.
If you're too old and your memory is faltering, you're "loosing experience". If your conginitive function is declining, your maturity is also essentially declining, all but in pedantic "maturity=age(ageism)" sense