I think people miss the point.
Yi is actually pretty stupid powerful. But he's a champion who can be shut down early, easily. And with coordination, this turns it into a 4v5 for awhile. High risk, high reward. When it reaches a certain point, Yi becomes incredible. But until he reaches or snowballs to that point, he's really really bad. And very punishable.
So yes, you can complain about him being CC'd and still killing your team. But to be fair, with the counterplay he has to prevent him getting there for a long time and for ending the game easier and earlier in addition to his counterplay even when fed that relies on a little communication, it's just the nature of solo queue to fall prey to him.