This situation is perfect for him, OKC would have been good for him too, Orlando was going to be a bad fit. Jabari doesn't have to do much but finish plays here. Dunks, open shots, play defense, this (I hope) is going to be plenty stress free for him. He won't be asked to come in and carry the load offensively, just play a role and get better. If he's as hard of a worker and as motivated to be great as everyone says he is, he'll get there.
For those of you saying Jabari is a better fit, why do you think so aside from him helping Sengun weak side?