Why does Zed have such a high ban rate?
Why do you think Zed has a high ban rate? Think about what can counter a Zed (No, don't put any bad matchups, they can be easily beaten with simple tricks). Stuff like Zhonyas can completely destroy a Zed. Zed is not even that broken. Vladimir pool, Master Yi Q even can shut down a Zed R any type of (untargetability can cancel his R). If people do complain about Zed one shotting someone, then they should know they can flash away after he finishes R and appears.