its really not even "who has the better jungler" its really just "w/e jungler get ahead first" after the scuttle changes there is next to zero way to recover in the jungle.. trackers knife is gone so u cant ward your entrances, the chances of your laners helping you is non-existent outside of voice coms. there is no wolf smite to grant vision of an invade.
if u die at scuttle. the game is effectively over for you as a jungler.. as u have no way back in unless the opposing team makes a horrendous mistake
as u cant contest scuttles, u cant contest your own camps because your behind in the jungle, you cant invade ( because your behind), if u gank then the opponent can either countergank or steal your camps. or wait for u at your next camp to kill you.
if u fall behind you literally fucked... even if your better and u only fell behind becuase your made overpushed and gave their jungler 2 free kills then he invaded you..
how u got behind does't matter.. but once behind there is really no way back in outside of waiting for a miracle or if your a champ that is good late game. waiting for lategame. there is zero catchup exp in the jungle.
its not "the better jungle wins" its "w/e jungler gets an advantage wins
and god forbid your counter-picked in the jungle, u make one misstep and its over.
the reason jungle is so influential right now isn't because "its too strong" its because if their jungler is ahead it means your jungler cant do jack shit because they have no way back in the game, outside of a miracle.
if u get behind.. and thier jungler player PROPERLY. your never going to get back into the game. and any good jungler can exploit this to completely and utterly invalidate the other jungle once they get a lead.
"junglers arn't broken", junglers just have no way back into the game if they fall behind
if u gank, he steals your camps, if u take your camps.. he can gank and get fruther ahead.. if u dont know where he is.. he probably waiting in a bush next to your camp to kill you, there is no way to defend against it unless your allied all come to help ward because riot removed all vision tools for the jungler.