If there was one, then you everybody must be rich from gambling. What you gamble is also what you risk. The risk will remain the same in any gambling site. The chances of you losing will always be higher than your chances of winning, this is because of house edge. Even a mere 0.5% - 1% house edge is enough to really burn your bank roll in the long run.
Yeah we will truly be rich if there is a site like that and i cannot call it gambling since we let us win always when we play at time but instead i will call them charity
, but in reality there's no way that we can win always since im pretty sure that site owners doesn't want to lose and go bankrup if there gamblers keep winning thats why as you said theres house edge to eliminate their luck if this will occur.