If we could just get approval voting implemented universally, maybe we wouldn't need an enforced upper limit.
"No person may be inaugurated as President if they are 70 years or older on the day of the election"
Neither party or area of the country would be impacted any more than any other, so there's no partisan angle. Just a few older politicians would be excluded.
We have primaries and qualifications for getting on the ballot, and while one might quibble about the exact details, I don't think most people would be happy if we somehow collectively elected a 10-year-old, or a goat, as President of the United States of America.
An old person doesn't have to care about a future career once out of office and can ignore bribes. (Yeah yeah reality might prove differently)
Ron DeSantis is 44 years old, quite close to that line. He is likely to be candidate for your presidency one of these years. You may not like him - or maybe you do - but he seems to be quite viable. If your former president does not get in the way he is likely to be the candidate for the Republican party and with that the next president of the USA given the dearth of viable candidates on "the other side".
Presumably there are advantages there too. Perhaps harder to bribe or threaten someone older (they don’t care as much?)