Ok lets say you want to play lee, xin, graves or any early game fighter even if you take one of the scuttle crabs, you will still be same level as support. Now lets say you pick something that is not good early, you will guaranteed to be more under leveled than the support. What is even the point of jungling at the point. I like Tanks and champs that have CC, i like to set up kills for my team with Naut, Amumu, Zac, Maok, Sej, but why would i pick any of these when i can just play support with mobis, roam and do a better job. It's pointless to jungle a farm jungler since you are too underleveled when trying the strat, it is pointless pick a tank jungler because the support does a better job, the only option are early skirmisher junglers. That's why i say its a shittier version than support, because a support can do a better job and have more diversity while doing it. Also next patch when pyke comes out, why bother playing jungle assasins, when you can assassinate people and not have to worry about dumb scuttle crabs.
Hope this clarifies what i meant