It depends on which game you're playing. If you play card game like poker, you can win, even on the long run.
It's the same for sport betting, you can win if you have skills for that.
I don't think that statement is entirely true, friend. if only playing gambling like poker and sports betting can win of course everyone will only play poker and sports gambling.
since the gambling game is based on luck, so gambling addicts don't just choose the two games, they play a lot of the games they like. and with the hope that luck is on the game they play.