I’m a HV jointer for northern power grid, started as an apprentice back in 80s.
I think onza has about nailed it with the tests. Whenever I’ve seen potential trainees at school they’ve been tested on:
Climb a ladder against a pole, maybe 8 metre ish, belt themselves on undo a nut and bolt then lean back and let go with both hands.
Make off a 3 pin plug on a piece of flex. Make off a piece of service cable into a cutout, after been shown of course.
I think it’s a great industry to be in, different places everyday. Just be prepared to work in all conditions at any time of the day.
Oh and great tip for leaving his phone in car