The key to balancing jungle is counter-intuitive.

The problem people have with the jungle role is that it seems to decide the outcome of the entire game. "better jungle wins gg"

So we keep looking at jungle with the wrong mindset. "Nerf Camp XP, Nerf catchup XP, Nerf gold". But where does that get us? It forces the jungle into a situation where farming their camps is reduced in effectiveness. So the while risky, Gank spamming is much more effective. But again it's not about the jungler getting so strong it's able to 1v9. It's about the fact that once the jungler gets ahead of the enemy jungler, He literally cannot compete. bringing the game into an effective 4v5 where one champ is fighting a massive uphill battle against his opponent and that has rippling consequences throughout the match.

My proposed fix is to buff camp xp slightly, and Crank catchup xp to 11. This is to stabilize the role. The jungler cannot have as much of an impact if the enemy jungler he is trying to shut down requires his constant focus to keep shut down. Because if your jungler can always catchup quickly to the enemy jungler, he will be able to counter gank without it just resulting in a triple kill, and will be able to pull off more powerful ganks of his own. Due to the early game nature of the champs that succeed in the jungle (exceptions exist ofc) This means that in many cases, if a jungler doesn't do well early it just fucks over the rest of his team creating an uphill 4v5. So what if we made it so jungle couldn't fall behind? They were always impactful. This would actually open up the ability to play late game junglers and would reduce early jungle effectiveness because you aren't pigeon-holed into early game junglers and even if you play one you can actually stay relevant for the whole game.

But in the end this is a question of snowballing. Do you like 15-25min games? Then you won't like my proposed changes as they are directly anti-snowball. But if you like the 30-50 min games then this is the best solution. This is a preference.

The Jungle as a role is an early game role. when its 35min in. Syndra isnt a mid laner, she is a mage. And the concept of jungler disappears after 20 or so min, and you are left with a champ of a given archetype with smite.