The true disadvantage of using a VPN is that if the casino catches you, your funds are going to get confiscated and then you will also be ask to submit your KYC. We shouldn't only turn off our VPN but we need to uninstall it for our own safety. I am sure that there are still casinos out there that are fully legal in our country.
If his location is included in the list of prohibited countries in the TOS then it is not recommended to use VPN access because if the casino asks for KYC it will not be accepted, so the account cannot make withdrawals or even the account can be frozen. He needs to weigh the risks before accessing an online casino using a VPN. Like your suggestion above, he may find alternative casinos that are legal and accessible without any prohibition rules.
Of course, you can find other casinos, but if there are few of them, then the choice will not be interesting!
However, such things as a VPN can always be regarded by the administration and security service of the casino itself as dubious, perhaps even they will suspect fraud. And all the same, in the end there will be insurmountable obstacles with the withdrawal of money from your deposit, or some kind of blocking of accounts.
I think that recently, when there is such a bear market in the field of cryptocurrencies as it is now, some casinos even make money on such a "perpetual" blocking of customer deposits. But they do it, of course, secretly from the regulatory authorities. So there are problems with VPN.