I have made some findings about this before if I remember correctly. There are people that have sued gambling sites before but the result has always been the gambling site winning the lawsuit. So just know that if anyone sue any reputed gambling site, the gambling site may win the case.
Secondly before a gambler will think of to sue any gambling site first you need to make sure that you have all the right, I mean the fault is not coming from your own side. Because most gamblers can just decide to sue a gambling site when he don't even have the right, and sometimes it can be that the fault is from the side of the gambler at this point they will be left with no evidence. Which is why the gambling site always win .
This path is actually tedious and time-consuming. And you have no assurance if you will indeed get the results that you want. Besides, ask yourself if you are ready to shell out money from your pocket? Expect a long battle from this because the decision won't come fast. This is why most gamblers will only end up ranting over social media or their thread, as going to the path of suing is not worth your time, money and other resources.
You're right a gambler is not meant to go to the path of suing the gambling site, because this can make you lose a huge amount of money sometimes the money you will spend in that process can be x10 the profit which you make in that gambling site that made you to think of going to the path of suing them, and of course the gambling site can be willing to afford whatever it takes just to make sure that they win the case, while you that happens to be the gambler will be finding it difficult to afford whatever it takes. This is why we shouldn't even think of suing a gambling site.