More like 25-40, menopause melts your brain
Voting age
Voting is anti-thetical to the furthering of dialectics, in this context, ageism would not be relevant, but only ideas.
How does voting retard the dialectic exactly?
Because voting does not explicit any analytical resolution of problems, just the underlying material conditions under which the question (vote) is asked. The only way to further the dialectics is through the opposition of contradictory theories : thesis/antithesis/synthesis. This can either happen democraticaly or
technocratically (there is no point in asking the general population about technical matters).
Also in an ideal situation, dialectics wouldn't be centralised, but anarchic (as in not relying on a central authority), only the relevant people for a specific problem ought to resolve it for themselves.
For example workplace democracy through council communism instead of simply relying on unions through a central governing body.
You're missing the point of democracy. It isn't a mechanism to find an "analytical resolution" to problems, it's a mechanism that gives citizens a way to further their egoist interests without having to resort to violence. Your technocratic utopia has nothing to do with communism.
16 sounds about right.
If talking about communism, it would be anarchic in nature, thus democracy would be useless since there would be no central authority.
If talking about transitional socialism, then most theories goes around the conception of the state (thus of democracy) as either Leninist (parlementary, so ageism is not relevant) or some other left-communist tendencies (often decentralised, so ageism could be relevant, but only for specific cases).
Not sure about others but I've gotten dramatically lefter since I was 16. Can't really explain it, but a lot of things just started to click, like when you first take algebra and none of it makes a bit of sense but you go back to it a few years later and it doesn't seem hard at all. I'm hesitant about letting 16 year olds vote, I felt mature as fuck back then but now I'm in my late 20's and now teenagers really do look like children to me.