Exactly, DNS was somehow like to influence your webface appear on your computer too as far as I know and not hiding your IP address, a VPN does. I wonder where you live but if that's a good thing for your country to ban all those gambling sites I think they have reason for that and yet you can still play anywhere, it's a good thing.
If the website doesn't hiding the IP, they will know who you are and know if you cheat using the same address. I mean, DNS is look legal tender if we use it for just to unblocked internet access?.
Please show me at least one gambling site where changing DNS is prohibited, lol. Personally, I've played in more than 100 casinos over the past few years and none complained that i using google DNS.
Are you use Google DNS mainly?, I mean if you somehow get ban, are you try using another DNS provider?, (cloudflare) and all was fine?