I would say I’m wiser now at twice the age, but I and most of my class at school had fairly reasonable political views from my recollection; maybe a bit naive and simplistic in a few cases, and a little bit of groupthink going on, and at least one die hard communist (though I imagine he still is, so I doubt that affects much either way).

16yo is old enough to do pretty much all the other big decisions of an adult, so why not voting, they’re not really treated like children anymore by our society.

Yup. Johnson and Truss were “worse” leaders, but that just means they were ineffective leaders. Cameron was disastrously effective and will be remembered for the devastating effect he had on the nation, fundamentally Johnson and Truss were his fault.