Almost every single casino reserves themself the rights to demand a kyc verification upon deposit or withdrawal of a certain sum of money.
My withdrawal amount was only 2.9 LTC. I have always played with crypto there and my withdrawal sum hasn't reached to the certain level which is mentioned in the KYC terms.
If you don't feel comfortable doing so, you should probably stay away from most online casinos.
I would give you the same suggestion if you were in my position, but you would make fun of it. I'm active in online gambling before you have joined in this forum. I have played at numerous casinos and I'm still doing it. Winz.io is the only casino where I have become a victim of such shabby KYC rules. My withdrawal sum is a few hundred thousand dollars at other casinos. I have made a few thousand dollars withdrawal in a single transaction. Those casinos have KYC rules too, but none of them ever requested me to verify my identity.
I've had a bad experience myself using the free spins on winz.io but I wouldn't complain about such basics to be honest.
Did you find it reasonable when they asked you to verify your identity? I believe you have seen the complaints of other users in this thread who was a victim of Winz.io shabby rules.