You can become a professional poker player, a blackjack expert, but you can't become a professional roulette wheel spinner, lol. We're just kidding ourselves. But even when it comes to playing poker. It's a very competitive game.
You can become a professional in unique casino games like poker and all the rest that has to do with competition. Being a professional player doesn't mean you have to win all the time you play, I think that is the mistake people make and you were also having similar mindset. Skill based games are the only casino games we can say people become professionals, in luck based games it has to do with luck all through and small analysis.
Skilled based game also depends on luck when you are playing with a pro like you. The cards that you pick will determine your luck. It's only if you're playing with someone that you understand the game better than is when you skill will make you win the game. As long as it's gambling, luck cannot be exempted.