With the easiness of the internet connection, people tend to play gambling in their homes or in any place they like. They feel that they are free to choose the casino, and they don't have to go to the real casino. They found that they can play gambling without any restriction, and with crypto, they don't have to fill KYC like what they did in the real casino.
There is still a restriction and a lot of people doesn't like about it. There are still KYC in other sites, it may be fiat or crypto currency. In terms of not having KYC, online gambling have a limit of deposit and withdraw which is sometimes so annoying, then the fees that is so high sometimes. For me, it is better to gamble with fiat offline though that doesn't have anonimity like cryptos do.
yes some casinos often ask for KYC but you are not bounded to gamble only on those casinos which ask KYC. There are many other casinos which do not ask for KYC and which are also very legit, you can gamble on those sites if you do not want to show your identity and want to gamble. These casinos which do not ask KYC do not have any limit and high deposits for the users.