Specifically, it is evaluated as almost impossible that someone could have accrued required experience before the age of 35,

while it is very much possible that an aged individual is mentally proficient.

Big reason for that is that the requirements also have age requirements, which ensures that nobody who is even 35 is electable today.

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...

Age related declines are absolutely guaranteed and presidents serve for 4 years and senators for 6.

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.

And in fact people who have greatly declined and are still leagues above most of the rest - because the rest was what it was -, are very real.

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.

They’re closer to their deaths than their primes. They are not leagues above anything.

Your statement seems to indicate that you cannot see that some people are more competent, lucid, capable, effective, wise etc. than other: such blindness disqualifies from discourse.

They make a valid point. People who have already greatly declined are only getting worse.

Robert F. Kennedy Jr., Trump, and Biden are all showing significant issues and they aren’t getting better over the next 4 years.

We are’t picking random people from a Walmart parking lot.

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.

If you have 5 maybe 10 years left you cant create a plan for the next 20 years and be around to defend it, explain it or refine it. You cant discourage or encourage to take risks.

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.