What they need to do is create an environment that suits farmers and suits pressure junglers. Right now, the only people worth playing do both. The season 4 jungle had constant up time on jungle camps but lower xp and gold (minus conservation from spirit of the elder lizard). This resulted in more clever pathing and you could play mind games with laners and time ganks in interesting manners, but farming wasn't a bad option either and it kept you afloat.
Unfortunately, right now everyone's butthole tenses at 3-3:30 in the game because of the obvious but very hard to avoid level 3 ganks. They're hard to avoid because of the level the jungler is at. Usually a laner is 2 or just turning 3 and the jungler has double buffs. Damage junglers just destroy everyone as a result
What i wished we had back was an easier jungle and jungle champs balanced around each other rather than balancing around the jungle itself. They keep camps really tough so that tanks can't just run amok and kill everything. Then they try to make them hit hard so Evelynn doesn't run around and kill everything. Well jungle diversity is the spice of life for junglers, and I'll take the diversity that the season 4's jungle had toward the end of its time and before patch 4.20. Quill coat was out, allowing tanks to keep time with damage junglers without losing too much health. Damage junglers were still damage junglers and could counterjungle and carry but the ramifications and consequences for the opposing jungler weren't as catastrophic as they are now. As a result we saw a pretty big spread of junglers at that time. I saw Zacs, Sejuanis, Wukongs, Udyrs, Lee Sins, Vis, Evelynns, Elises, Jarvans, Kha'Zixes, Pantheons, and even wonkier stuff like Cho'Gath. I'm sure new Graves would have found his way into that jungle as well.
When health and mana for junglers is high but xp and gold is kept low(er), Jungle has the most propensity to shine as an intellectual role. You really were more capable of outwitting the other guy rather than brute forcing with some Lee Sin lvl 6 instakill nonsense that we see now.