So did you see professional gamblers specialised on luck based games ? They are most on sports/Players versus Players games .. games that requires skills that can be managed to get profit to your side.
also that things requires hard work to get of learning and aquierring these skills. That is why common non really implicated player heads to simples luck based games with hope to made profit from.
Even though people who have expertise in gambling I am not sure they will really win in the end, for example now winning is not certain tomorrow they can indeed be so on. Gambling is like a spinning wheel, in which there are winners and losers always take turns.
And that's why I say gambling depends on luck.