To fix jungle:
Put vision back so that laners can answer heavy gankers.
Screw pro play. I need to be able to ward up HARD against heavy gank junglers, particularly if my jungler has to wait until later to help me out. I dont watch LCS. And I loathe losing hunters knife and sightstone just so pro play can be less boring.
Put XP back up where (hard) ganking isnt the only functional style.
Nerf abuse cases: Yi, Udyr, Jax, such that hyperfarming is not overincentivised.
If the three jungle types, gank, farm, counterjungle are equal strength, there is a lot more diversity and life in the role.
You have to put the vision control back before that can happen though.
The issue has two parts. High pressure junglers are strong both because other options cannot glean sufficient exp, and because vision has been GUTTED over time.
That's why jungling is simultaneously the most stressful and the most idiotically impactful role in the game despite feeling awful to play.