I don't see why people keep complaining about KYC in an online casino. If it is what is required to secure the money of users in the casinos it is a good idea that all casinos should make KYC mandatory. Truth is i can't trust any casinos that don't make KYC compulsory because i would freak out with time. Like how can you trust a platform that don't take security seriously? Risking your money to platforms that would do nothing when something mistakenly happens to it.
I don't think KYC is a feature to secure users' money though, can you describe how submitting personal details helps the casino/platform that you use to improve how they store your deposit? I believe even if the casino doesn't know who you are, they can store your money carefully with techniques like a multi-sig wallet, no single point of failure, making sure no workers can gain access to their hot wallet, etc. KYC details are just one way for them to verify who you are, so that either they can comply with the law or do an investigation if somebody is suspicious. I believe there are other ways to verify whether somebody is a bot or not without doing KYC.
One of the most obvious issues with KYC in any platform is the risk of data leaks. There have been tons of database leaks in the last few months or so. You're lucky if they don't leak any sensitive data, but there's no guarantee it won't happen in the future. Not to mention the risk of data abuse such as selling your contact details to other parties without your consent like what happened with Facebook.