Veigar is not broken. There are so many better cc abilities in the game than his cage. You think it's bad now? Don't you remember that a couple of months ago it was instant cast? No warning, just pop you're stuned, you're dead.
Never mind that Sona has a stun with only a marginally smaller area of effectiveness, but it also stuns everyone in that area for longer than event horizon. What, going to argue that you have to be right next to her? Fair point, she can't put it anywhere she wants. What about Zyra? Her stun is also a knockup, and sweet Christ, does this thing have a huge AoE. I know these are ults, but I hate people like you that say his stun is the best cc in the game with a 1.5 second delay on it, but a month ago thought it was garbage because it wasn't instant cast anymore.
He has counterplay; in fact, I met a diamond smurf that the new Veigar couldn't touch. When that wall particle effect comes up, he is out of the way. Even if he's inside the range of it, he'll still be able to sidestep Veigar's W and probably his Q... his W has a huge delay and isn't nearly big enough to guarantee a hit if the stun doesn't land. Your Q at lower levels is a joke, so even if it does hit, it would have been much more effective to last hit a minion with it than to poke with it.
Trust me, I'm a Veigar main and have been pretty much since the rework dropped; you're just mad because he was unpopular, so no one knows how to deal with him at your level of play, so when he starts popping up, people think it's unfair instead of just doing what they did when he fell out of favor with the community. The same thing happened to Kayle a while back, and recently happened in Bronze with Xin. I just say which division because it may be different at Silver and higher.