Maki needs to deal damage
He doesn't have Rek'sai's global mobility and spider sense that would allow him to function as utility bot at any level of play. More so, he can barely jungle after his rework, and after this Arcane Smash and Sapling Toss nerf he probably won't be able to do so at all leaving him in even worse position than Rek'sai - CC focus is fine if you frequently force 2v1s as a jungler, but in lane it is meaningless if you can't back it up with damage and waveclear. Rooting and knocking your enemy is pointless if you still lose a trade.
If he is too strong - no if's there, he is - nerf his insane tankiness to give his enemies a fighting chance. I see no reason why one champion should have 20% bonus tankiness, Chosen of the Storm-level healing and a god damn Playfull/Trickster at the same time.
Personally, I'd just make him targetable during Twisted Advance and call it a day. Untargetability is something that goes as much against tank archetype as you can get, and ability to outplay his enemy most damaging spell assassin-style is a big part of what makes Maki so oppressive when strong. It could stay and unstoppable dash, so he doesn't suddenly become the most kiteable of tanks, but that's just another lever to pull if he is still too strong.
