Should it not go for the reverse as well? Some 14 year olds are smarter than a lot of 30 year olds, but I don’t ever see anyone advocating for them to get voting rights.

I see both sides. There is no good way to cognitively test either, as that could be abused as well. Age limits would help, for both voting, as well as term limits for the politicians.

That said, I believe there is far far far more wrong with the country which if fixed wouldn’t even need any of the above to be significantly better.