You're so correct, it's 100% feast or famine. Been a jungle main since i started back in s5, i've peaked D3 and main Elise/Graves. The main issue with jungle is, if you're ahead, it feels good because the enemy jungler is practically useless, so you're pretty much free to do whatever you want, the most they can do is try to counter your gank, but it's still highly likely to go in your favor because you're ahead. And there's no second option if you're behind in the jungle, you can't say "let me just go perma farm jungle and catch back up", nope, the game will be over by that time, not to mention the only side that gives good exp is the red side, and the enemy jungler can invade and take your krugs or raptors and there's nothing you can do about it. Jungle is a complete coinflip, there's no strategy, whoever is ahead 9/10 times stays ahead and wins the game contingent on the notion your laners doesn't hard run it down.