Even so-called premium, paid VPNs share IP. By the way, in order to feel safe and secure when playing on casino with VPN, you should choose a VPN that offers dedicated IP address. By doing so, you'll be the only one who uses that address and you won't have to worry about blacklisted and shared IPs.
If you are using dedicated IP it will help you a lot like if some addresses are under suspicious and if you connect with the same one it can be problematic for you but I also use it and haven't faced any problems because it's paid one most probably.
You are right, using a paid for, and dedicated IP are much better than the free ones, and much more even better, if you use the same beginning from the registration process and continue to use it all along, the casino might or may never really know that you are using a VPN.
But then again, have you thought of what problems may arise when the casino, for some reasons ask you to submit your document for KYC verification, and the location on your document is not the same location your IP address have shown the casino since beginning of your registration there, and also, it happens that you are playing from a place that is restricted by the casino, which happens to be the reason why you are using VPN in the first place, don't you think this could be a big problem for you, most especially, if you have some really big amount of money in that casino??