Maybe the casino he alternatively used is not really implementing 100% the web3 feature on their casino since base on his claims there's still a log in feature on that casino.
Maybe that casino allows users to have multiple options, normal account with password and another type is with Web3. You can create your account with password, then late decide to use Web3 wallet and can connect that Web3 wallet to your account.
But in Metawin they can simply do what you have been said and that would be the most easiest way for people to gamble without getting any much hassle just like signing up an account before you can enter their casino.
No dependence on the platform as custodian of our fund and it's very basic rule for safety and security of our fund. It is like double edged solution but if we are careful people, with good knowledge on tips to create strong password for Web3 wallet, make good back up, we are all set to be safe and secure, by ourselves.
Anyways everything is good since for sure as he or we play on metawin we could really see how convenient the web3 feature for gamblers.
Web3 wallet and connection to platforms from trading, betting is convenient and MetaWin did great job to join the trend which, in my opinion, will continue to grow more in future.