KYC is implemented by crypto exchange because they are required to do so by the government and it's done to prevent scams  and money laundering according to the reason they stated about the need for KYC. If you are giving out your details for KYC purpose it should be to a reputable exchange, that will reduce the risk of your details being used for scam purpose. Should you fear about your details going into the wrong hands, yes, but it can also go into the hands of the government authority that can investigate you if there's any problem that was traced to you. If you want to avoid KYC on centralized exchange, there are some that allows you to transact freely without requesting for KYC unless you make deposit that was above your account limit.