hmmm, i disagree with basically everything you just said
JG is without a doubt a interesting role for sure but it's also asked to do quite a bit and because of that I think it is actually slightly under tuned tbh. I don't play JG but a JG is asked to do a lot across the entire map and if they do it well they should have a pretty dynamic and powerful impact on the game and if they don't do well you should feel it around the map.
There are a lot of different JG champs atm and not all can lv 2 gank just so thats clear and the ones that can lv 2 gank are fairly obvious so you should expect the possibility of it. Generally it's snowbally jg's or JG's that have early CC, I mean in theory it's possible for a Yi to lv 2 gank but if there isn't a lot of CC on their team it's actually a waste of time if they did.
I would say you should probably play JG and see for yourself