Isolation: No clarity for opponents
You don't know if you're isolated till you die in one fucking hit, even if you are like 2 inches from your teammates.
Lacks clarity/clear weakness for opponents to exploit.
It'd be like when TF uses his W, only he can see the card he pulled until thrown. Or if Draven's Q didn't have a visual effect and you suddenly just took 5000 damage from one AA. Or if Jinx has Rockets/Minigun in hand
Bring clarity for enemies.