@Linkat,
In my view, there is no direct link between a person's age and their political education or sense of responsibility.
By lowering the voting age (18 years, in local elections sometimes 16 here in Germany), young people would have a real right of co-determination and thus be able to help shape their own future. After all, most political decisions are very far-reaching and in some cases irreversible. If the voting age is not lowered, young people will have to bear the consequences in their adult lives of decisions in which they could not participate - because those who are involved in the political decision-making process know that they can make a difference.
An example of the success of lowering the voting age:
in Germany mayors are elected directly by the EU citizens living in that municipality.
In a middle seized town (Monheim, 50,000 inhabitants) teenagers founded the youth party
PETO – Die junge Alternative ("PETO - the young alternative"). Their leader became the professional mayor in 2009, was re-elected twice (last time, three weeks ago, with 68.5% of votes against three opposing candidates). He's 32 years old this year.
In the town's parliament,the youth party got in the last election 56,8 % of the votes, followed by the conservatives (CDU) with 22,7 %, the Greens with 9,4 % and the Social-Democrats with 8,3 %.
Public transport is free for Monheim's citizens, kindergarten and all-day care for children/youth is free ... and the city budget has no debts since 2013.