

Yes, but we are not filtering for maturity and capability in adults. So if this is the argument then imo it is flawed, since we’d filter for something just to stop filtering for it after a certain age.
If one wants to filter for these things then it should be applied across the board. However we are not doing so for good reasons (I can provide some if needed).
Yes, this is indeed an argument that shouldn’t just be ignored. And honestly this should simply never be the case, regardless of age.
I’d break it up into two parts. Official election material and just general advertisements/media. The first one typically is already quite regulated and arguably for the benefit of all should already follow standards that are not harmful to children. The second one seems like the problematic one. However I’d argue that even children are already to some degree getting confronted with what’s going on in the world. Anecdotally i can say that even at elementary school age children seem to be (to varying degrees) at least rudimentally aware of many things. To give a recent example like when Israel bombed Iran.
We have things like cigarettes and alcohol where we impose age limits, but those are directly harmful things. Hard to argue that voting in a democracy is harmful. Sometimes there might be anti democratic parties (like the afd here in germany for example), but in those cases you’d think about banning those, not taking away the ability to vote. Maybe you or someone else could give me an example of something positive being banned based on age because the state/society can’t provide protection from something secondary.
I would also add that advertisement to a young voting base wouldn’t exclusively need to be a bad thing. Take free school lunches for example. If as a politician you run a campaign on that for example you are banking on gaining favor from a voter base that only indirectly is affected by it. The people directly benefiting from it can’t vote for you.
They have a voice, but no vote, which is what matters for the politicians in charge. Also “just 2 years” falls flat since my argument is not about the lowering to 16, but abolishing it in general. So for the sake of argument for example an 8 year old, which would make it a full decade. In practice even longer, since elections aren’t every year and you aren’t guaranteed to have one in the year you turn 18.
And you are right that even 30 and 40 year olds are affected by these issues, but i don’t see how that would be an argument against it. If anything i’d see it as an argument that children should also have a say. We also don’t have an upper limit after which you aren’t allowed to vote anymore. And for obvious reasons it would e.g. be impossible to have a rule that says x years before you die you aren’t allowed to vote anymore, since you won’t suffer all the consequences.