Comment by makeitdouble

Putting it as a separate response:

The weight of cognitively restricted people and non-citizens in the voting process is less and less a theoretical issue, and would merit a lot more discussions IMHO.

Countries like Japan or Korea are getting into demographic phases where elderlies account for about 30% of the whole population and their voting power is tremendous, but we probably have no idea how good or bad the result is, and just cutting their voting rights as they reach some level of impairment would also be a seriously dumb move IMHO.

And on the other side as the fertility rate plummets bringing in more foreigners is an obvious option. Except these foreigners might not want to give up a stronger citizenship (e.g. an EU passport is way more valuable than a Korean one) just to get voting rights in their resident countries, and their kids will have a stronger incentive to go abroad as soon as they can if the country makes their life harder yet.

Partly in reaction to that, Korea for instance gives voting rights to foreigners mostly by virtue of residency.

We're entering very tricky situations where there's more imbalance between the ones holding decision power and the ones bringing the most to the table, and there's just no simple solutions nor any direction that is straight "good" or "bad" or unthinkable.