A huge part of the poor youth vote attendance is due to them not feeling represented by geriatric nominees.
I’d say a larger reason is that they’re simply not interested in the politics at that age.
I know I didn’t care at all who was in government when I was at that age. The fact that they were a couple generations older than me wasn’t a part of my thought process.
I simply couldn’t be bothered to even think about politics or governments.