But, where does a young person go to get their (engineering) training these days (and don't tell me University ... I'm talking about proper training)? Who's going to (be able to) take over when "us lot" have all gone?
Block release college/university, on the job training, cpd to name a few. There's one major difference between military and the non military, usually there's nothing to stop an apprentice from completing their apprenticeship and the next day deciding they want to work for someone else. (it’s one of the many reason’s apprentices are kept sweet) Correct me if I'm wrong but waking up and deciding you don't want to do the job in the army is still called desertion!

Some apprenticeships have got around the problem of retention by either demanding that the apprentice pays for their own training or having an similar scheme to sponsoring at degree level where the trainee agrees to work for a certain period or refund their training expenses on leaving.