Here’s my take on it.
From the age of 12 I was travelling unaccompanied on all forms of transport - UK and abroad, so yes, I would be seen off at the departure point but after that it was up to me to work out what to do. It would have been explained thoroughly so I understood what was happening.
So, for example, I might be collected by taxi from my school, dropped off at the railway station to buy my ticket and find the train and board it, get off at the right stop (usually with all my belongings - not always!) and be met at the other end.
Or, it might be a taxi, train to London, find another taxi to West London Air Terminal, get the bus transfer to Heathrow Airport, check myself and my bags in, fill out the immigration forms etc etc, board flight, transit through the next airport for a connecting flight, transit through another airport for another connecting flight, keep my tickets, passport etc safe, track down my bags and deal with it when they got lost, then a taxi from destination to home.
And all this was fine if it went without a hitch: when it didn’t, I had to sort it out and get on with it as best I could.
Another time I was escorted as part of a group of unrelated school children, to Paris before being put on a train on my own, to Toulouse. The return journey was overnight, (and yes, even being in the top bunk/couchette didn’t completely protect me from the exploratory hand from the bunk below, but there were many other people who would have come to my aid if needed. I just rolled over and faced the wall and it soon stopped) and then I had to get myself to a different station, ferry and train…
And so on, and so on.
The outrage over these kids is bonkers. They are old enough to vote and decide who should run the country but need their hand held to catch some trains?