Kyrie is an immense talent. Nobody would be denying that, but he's not as good as he thinks he is. During the recent stretch since the ASB, he has turned into a pylon on defense again, much like Harden. I don't appreciate players like that, because what are sorcerer moves on offense good for if you give up an easy 2 on the next possession? The record with Kyrie and without is indeed alarming. It's not the be-all end-all argument, but it certainly means something since the sample size is not that small.
The bigger issue with Kyrie in general is that we have the worst "star" of all on-paper-contenders. (TOR: Kawhi ; MIL: Giannis ; Philly: Embiid ; GSW: Curry/Durant ; HOU: Harden ; OKC: George ; DEN: Jokic). We will never win with him as our #1. Plus our supporting cast is not as good as we thought it was going to be. Tatum has yet to take the next step (which is fine for his age). Brown didn't progress as hoped and Rozier turned into a pumpkin after rocking last years playoffs. Hayward takes more time to recover, if he ever regains the form of 2016-17.
We have 2 different paths we can go this summer: Either hand Kyrie and AD/KD the keys to this team or if they leave, go with youth and go back to a formula where I think Brad Stevens is most comfortable with. Developing a team with young players and some secondary role-players without star allures (like a Horford type). He has shown that he can thrive with such a model. A team of Smart-Brown-Hayward-Tatum-Horford wouldn't be all that bad. We'd still have the (hopefully #14 and #17 picks this year) and the lotto pick by Memphis which may turn into a #1 in 2021.
Let's put it this way, if Kyrie re-signs: I am cool with it, because it likely comes with getting either AD or KD. If he leaves, I am also cool with it, because I don't think he's nearly good enough to be worth all the trouble.