I'm not talking about one country but every country. It seems like a higher voting age would benefit republics. People who are young don't have a lot of experience and often have never worked or run businesses. My argument is that the young are not very responsible. Currently the voting age is I think too low. Most countries set it at 18.
Here's a link showing the current legal voting age in most countries:
In the majority of states, the legal voting age is 18.
www.worldatlas.com
I don't really think age is the issue.
I think the problem is the political system and the show it has become. Is there anyone who can't recognize that politicians say one thing and then do another? that they in many cases seem more interested in maintaining power rather than finding solutions? More and more countries seem to lean towards dictatorship-style governments with lots of surveillance of people etc.
For me personally I have little confidence in any politician and political system and it is more a question of trying to vote for the least incompetent/corrupt one, that hopefully has humanity's best interest in mind.
Whether you can vote as an 18-year-old or have to be older, I don't think makes much difference in how the system (show) works.
We need a political system which are intelligent and which focuses on solutions, which we have very little of at the moment. The environment and animals are doing badly, war is ongoing and probably worse ones to come. With the technologies and resources we have available, I think humanity as a whole could do a lot better than we currently are if we had better political systems and a more healthy foundation. Money and power aren't good motivators for reaching it I think.