Absolutely zero you can do now as jungle with a single inter on your team.

Get awful people like a Mordekaiser giving 3 kills to a Rengar in 4 minutes despite my pings and chat telling him to be careful and not push mid lane without vision against a Shen.

Rengar with 3 kills means that even as a tanky champ like Trundle with rushed tabis I can't even farm my jungle because the Rengar is 1-2 levels up on me at any point and I lose 60% of my health to a single jump. That Rengar proceeded to collect kills from other lanes on top of invades on me.

This is not just Rengar specific. The jungler with losing lanes cannot farm even his own jungle in peace at all, falling further and further behind and not being able to do anything.

On another game with Evelynn I helped my team get first blood off an invade but died in the process. The Shyvana who died has a shorter run time to red, gets 2 first, comes to blue since my lanes didn't want to leash for me after dying and I can't fight her at lv1 and it becomes a process of getting invaded by an enemy that outlevels me at every point because a stolen buff and 2 scuttle crabs I can't contest with afk lanes means a permanent level lead.

If you can't play the game off a single level lead since unlike laners you don't have the safety of turret to farm and soak xp, what the hell is a jungler supposed to do? Being strangled out of camps means I'm also gold starved to have enough warding to keep track of the enemy jungle and further delay any items to have impact or be able to duel/contest.

It's a truly infuriating experience how trivial it has become to invade with a level lead throughout the game and with very little consequence.

Jungle is no longer fun, there is virtually zero catch up and unlike laning where your own failings set you behind with the opponent, it is 3 of your lanes' ability to fail on top of your own that can completely set you behind.