I think there are few people who have achieved such a thing, and even then I think few of them would be willing to comment on it here. Of the cases I see, many of these people have achieved such success by luck. So it's a pretty risky thing to try.
Winning jackpot happens once in a life time and only a very few had made some good amount of money when it comes to gambling in the online space,there might be big whales in the real world but here all i hear is the losing streaks from the players and i have seen some lucky fellos who won some.
Whales do exist but it would not mean they can easily exploit a gambling site, they have bigger bankroll which gives them bigger risk to take. That's how game is fairly played, people risk an amount to win an amount and it's like make money out from your money. They have their own way of making money and I can say it's risky since only a certain number of gamblers succeeded over the total gamblers.
Maybe let's call them the gifted one, they make easy money because they love to take bigger risk and they use their intelligence to make fortune.