That's not always the case. Some people doesn't care about these things like KYC and will give out their information when required/asked/needed. While others may hesitate, but still do the same, because they need to use that particular site/service. Tbh, I personally don't trust any centralised exchages but I have accounts that are fully KYC verified. I don't have any other alternatives to do my transactions, so I'm forced to use these (not because I trust them, I don't), not because I trust them but I don't have any other choice.
I have one regular practice, and that is to always hand out my kyc documents for verifications immediately after my account creations, this help me to overcome alot of stress along the way since i dont know which casino i have the luck of hitting my first 1000x multiplier that make me the jackpots winner and want to withdraw on $100Ks without problems.
So for sure anyone can do that as long as you have nothing to hide and you trust the casino, making sure you give your documents to only reputable casinos, this will definitely make alot of sense solving all this KYC issue's.
That might look like a good practice but I don't think I am comfortable with that in as much as I know that casinos that want to reap you of your money will always look for excuses to make sure that you become their victim.
I am very careful about what casino I am using especially when the casino is not in this forum so in case I have a problem, I can easy settle it with the team here with much stress. You will need to be careful about casinos that are not in this community because of anything goes wrong, the team might decide to delay or give a reply to your problem.