I feel that it’s safe to share KYC data with Roobet, because they’re taking extra precautions for protecting the user’s KYC details eg using 256 bit encryption, hence there’s very little chance of KYC details ever getting leaked.
The 256-bit encryption isn't an extra precaution but it is pretty much an industry standard, it's being widely used. You can see that Roobet is using it for the SSL/TLS, so it is surely safe in terms of transmitting any data.
if a casino in this case Roobet has proper mechanism to safeguard our KYC details then there’s no harm in sharing it with them.
Pretty naive to say there is no harm, there is always a risk for everything that is shared online on any site.
However, please note that electronic transmission or storage of information is not always 100% secure. Therefore, despite the security measures that we have put in place to protect Personal Data about you, we cannot guarantee that loss, misuse, or alteration of data will never occur.