As someone who used to exclusively jungle but now mains support yuumi i can tell you exactly why i no longer jungle which is all the champions i play are slow starters that need level 6 or struggle to clear camps in a decent amount of time so if you make the mistake of say starting blue as eve then a kha, lee, jarvan ect walks out of new fancy bush the only thing you can do in that scenario is die and since xp catchup is gone your basically deleted from the game unless you get lucky and the jungler never ambushes you again.
Comparetively i can be much more effective as a support and since the incomes about the same that doesn't bother me so much.