Why is Zac's ultimate so bad?

It seriously isn't even worth having as an ability. Everyone in the game is able to dash out of it because it's such a small circle it's easy to dash out of.

I seriously don't understand how Riot expected his ULT to work when he has no CC abilities prior to using his ULT. His E knocks up for 1 second at most which is about the amount of time it takes Zac to charge his R, but since you can't just E into charge immediately it's really only like a .75 second knock up which easily gives the opponent enough time to just dash out of it.

I'd literally rather have to have it charge up to 2 seconds, but it grounds opponents, because at least then it's useful as a ground ability where you occasionally get somebody stuck in it to bring them back with you.