I think the default purpose of KYC is controlling money laundering and funding of illegal things. in the beginning, Bitcoin promised anonymity, we have now come to the conclusion that it is KYC needed almost everywhere. sounds paradoxical, doesn’t it?
KYC is needed if you want to cash out crypto for FIAT.
If you just want to swap or withdraw crypto, why would KYC be needed?
Also, do not hand any info over to any "business" that doesn't have a business number. They can do whatever they want with the info, like sell it, and they have no accountability.
Most of the gambling sites/sportsbookies which are accepting fiat aside from crypto, are implementing KYC to their clients.
The player should read first the ToS or FAQ of a sporstbetting site/casinos before playing.
This is the reason why many are getting surprised upon withdrawal because they forgot to check the terms of the site.