I guess this is a question better raised to OKX itself. I assume OP isn't in any official way connected to OKX.
The question was generally for almost all centralized exchanges that do demand personal details in the name of KYC, not just OKX, because that is what they always said.
Anyway, I think this isn't so much about your funds' security as it is about compliance with regulatory policies and laws. They're left with no choice. To be fair, however, it somehow adds to the security of your funds because your account is now connected to a particular name, face, address, phone number, and so on such that whenever there is a suspicious activity going on they could temporarily freeze the funds therein or certain functions pending identity confirmation. If it doesn't match, then they won't provide access. It has its pros and cons, of course.
I understand your explanation now, and my question has been answered.
The disadvantage here now is that after submitting all these details on KYC, they will fully control your funds, and there is no guarantee of getting your funds back if the exchange is hacked or if something happens to the exchange.