Your opinion on voting at 16 will probably depend at least partly on whether you are a parent and, if so, what sort of teenagers you have.
(I agree with the rest of your post prior to this bit by the way!)
I've two boys (14 & 17) - both are pretty switched on & generally good boys (apart from usual teenage shit...).
My eldest is v interested in all the political goings on and is desperate to be old enough to vote (he'd vote leave fwiw, and so would his girlfriend)
He turned 14 just before the EU ref and got caught up in it all as it was a big thing at school which is great - he even got up at 4 to watch the last of the results coming through & was late for school so he could see David Cameron's speech!)
Then there was Trump, then TM's disaster (& JC's hero worship), then everything since.
I think his generation have been lucky in a way to have been in their formative years during such a politically massive period as he's definitely far, far more interested & engaged in politics than I ever was.
But! He was also all about the memes and the hilarity of disruption (as are many teens) - so would just have likely have voted for Corbyn or Trump 'for the bantz' rather than making a heartfelt, somber choice.
So (after my tangential ramble...!) I think you're right.
If you've got kids who are very sensible & mature & recognise the gravity of consequence of their vote then you'll obvs be ok with 16 yr olds voting.
But I do think that in all honesty, the majority of 16 yr olds are most probably more like mine - and I wouldn't have trusted him an inch 😳
Now that he's nearly 18 he's grown up a hell of a lot in just the last few months & I'd absolutely trust him to be serious now & make an informed choice.