A good way to separate your money, though everyone has their own perspectives about this matter and I also agree that 2fa provides an extra layer of security but on your case I also get that point in separating your wallets as maybe you have one for investment, one for savings and one for your gambling, just saying the possibilities of how you deal with your money.
And for sure, it's not only you who are doing this, especially y those who are conservative in protecting their assets.
Using different wallet for gambling and savings is indeed good but it doesn’t increase the security of your account you are just using different wallet. It only minimize your losses when your account was hack.
I think 2FA and SMS verification are already enough safety precautions for securing casino account. We usually don’t leave balance on our casino account so I don’t see this security concerns as major concern. I’m gambling since 2016 via online casino and I didn’t experience even a single case that my is hacked. I don’t use any extra security aside from my password on my account.
Our casino account will be safe if you don’t login from links provided by other user. Always bookmark the official website and you will be safe even without this extra security.