unfortunately that is probably the case more often than not
that's why KYC policies are not the ultimate solution and can even be harmful by incentivizing a parallel market for people's documents.
That's an alarming thing tbh, for just a cent people are willing to provide a dangerous stuff here. I think there should be more verification process other than KYC that can implement more stricter rules towards account but if that happens I think users are the one that will elusive for such a site or a casino.
Unfortunately KYC does cause a lot of people to leave, because there are other alternatives that doesn't ask KYC at all. I would say that even if you asked for a video of that person, they would just pay for it and get the video as well.
I am sure that weekly image requesting would be terrible for many people and they wouldn't want that and leave as well so it would be a terrible request as well. All in all there isn't a solution to this where you have a certain guarantee that it’s the same person but also keep every single gambler here as well. Either you lose gamblers or you let it be and do not care what others are doing to get that KYC.