I agree on all what you've said.
Such proposal could be formulated like this:
Only intact families should be entitled to vote democratically.
Which in addition

1. have their household in order (no debts)
2. have a job, either family work or commercial work

By ‘intact’ is meant:
Man and woman live together in a household with relatives (either their parents or children or siblings or other blood relatives). Or husband and wife alone, who already have adult children or cared for parents who have already died. In other words, they have fulfilled their intergenerational contract.

Verifying this qualification or form of community is easy because it can be proven by

• Citizenship
• Register of residents living in the household
• Information about freedom from debt
• Verification of taxes payed (one could include - maybe - a barter-system as well)
• Documentation of social welfare payments

This would protect all other data.
No morals included. Just facts.

All those who do not live with a family, who do not have employment or do not work in the family, who are too young to run their own household, who live on social welfare, who do not have citizenship, are excluded from the right to vote. They are thus relieved of the burden of having to make an intellectual effort on issues for which they lack practical experience and skill. At the same time, however, they are incentivised to make their participation possible if they marry, look after elderly parents, start a family and are debt-free.

We know, that this would outrage many people, don't we. We know that it will not be realized by the current zeitgeist.
It's not a ready proposal and certainly lacks things which I have not thought about.