Partly why I'm against anybody over retirement age taking office even if it is a heavy handed approach and could be seen as age discrimination.

The odds are too low of anybody getting meaningfully punished while they get to openly setup their entire family for generations using means and information not available to any normal citizen.

And while not guaranteed they are statistically more likely to suffer age related cognitive decline while still in office.

Probably the best age limit argument I've heard really: whatever retirement and pension age is, for public office that's the limit.

It's nice and clear, has obvious motivation and obvious sourcing.

Also obvious incentives: e.g. after your political career you will live with the system you helped build.