it makes me think
are there "good" gamblers? or its always luck?
maybe the ones who manage emotions and bankroll are the good ones
There are good gamblers though you can only find them in games which rely on a combination of skill and luck like poker, sports-betting etc. They usually end up earning tons of money and quit gambling.
I do not think these people completely quit gambling. There are lots of professional poker player continues to gamble even after winning huge amount of money. And many lottery jackpot winners even engage more deeply in gambling after receiving their winning money.
You won't find good gamblers in games that completely rely on luck for obvious reasons.
That is because luck based gambling games are different from combination of skill and luck games, since luck based games result is random, many players often lose more than their winnings.