Just like 16 years old people can’t vote because too young, 80+ years old people should not be able to vote, most of them are too distant from everyday reality of younger people to be able to take a wise decision for the community and also often stick with (way too) old ideals from their years
Who decides how old is “too old?” And what happens when the people approaching that age decide that young people (18-30) are the real problem and remove rights from them in retaliation?
This is the sort of thing that people shout in anger into the mirror at night, but any actual plans fall apart immediately.
Never give your political allies a power (in this case, removal of voting rights) you wouldn’t also give your political opponents. Your “side” won’t always be in charge, and what sounded good to yourself may be terrifying when wielded against you.
I think the average life expectancy age is a good point. It would encourage people to work to increase life expectancy because it widens the voter base. It would mirror the exclusion of younger peoplefrom the voting process too.