Those "multiple people" don't include you, it would seem.
And having just spent three hours watching Han's stream and seeing his Quad get blown away after a couple minutes in just about every match, no, it did not look remotely OP to me.
you have barely played the game tbh. When every top player tells you its overpowered, you can believe that its overpowered considering your very limited experience with the game.
It comes way too early and is way too good for its cost. It wins games very easily. Actually, i wonder if you have played against a half-aware opponent using the quad in a 1v1 or 2v2 scenario yet. I kinda doubt it.