Not every site requires KYC immediately, I'm betting on a popular gambling site that's in the forum and yet they don't require a KYC, I can gamble with an email and been consistent for years already. Well, maybe our location differs and they have set of rules per country.
Does each site adjust the rules according to regulatory policies based on the user's country, I think not because there are several factors that users don't need KYC including:
- no history of suspicious activity or violation of regulations
- low withdrawals
- no exploiting bugs, other cheats.
But many gambling sites have to complete KYC from account registration.
I think they have a standard policy, and as a gambler, we need to comply with those policies.
They will only base on the country to determine whether a certain country is banned or accepted in their gambling platform, simple as that.
Now, if they will require KYC, that should be for everyone since KYC does only stands for "KNOW YOUR CLIENT", which does not require a user to be suspected before they are required a KYC.