With that said. It is a proof that submitting KYC should depend on the website that you are using. KYC is helpful even though you are not exceeding 2 bitcoin per day in withdrawal because it will make your account more secure since you have a proof of ownership to your account because of the identification documents.
KYC is not going to make your account any more secure that it already is. Your account is linked to your email and mobile phone number, and as long as you control these accounts your exchange account will remain secure. I don't think that sending your ID documents to unknown people will help in increasing the security level of your account.
You have the wrong idea about KYC. KYC will not prottect your account, at least not in technical security sense, it's about protection of personal data and prevention of illegal activities like money laundering and similar. KYC should disable potential fraudsters that also you can make a victim of their activities. And based on.KYC you have a legal protection.