I'm trying to understand your concern for players who play regularly, especially if large funds are involved the comfort of later being required to have KYC might be better, but fulfilling KYC at the beginning because it's easier than if it's in the middle or when you're about to make a withdrawal, that's something new for me
I am hesitating to use new platforms because I don't know they have back doors that are risky for me and my identity as well as money. I am not ready to submit KYC on a new platform because why I have to leak my information even I don't know I will use that platform for too long.
However, it is different thinking if it is a big platform and I actually decide to actually use it for my trading or gambling. If their Terms of service, KYC/AML policy have terms to require KYC at some points, I would like to submit KYC and wait for successful verification before I start to use my account and make deposit to my account. It is safer for me and at least I have belief that I won't lose money because my KYC is failed.
Of course, if a platform is scam, they can run anytime later even I verified successfully but it is more common with new platforms.