Gambling covers a wide range of games so to me it depends on the kind of game you are playing. Sometimes where luck rules mostly like dice games, even a "hard worker" can lose massively.
Maybe another very important aspect of gambling is discipline.
This is how important to know what we actually been doing, and very often to say that hard work won't really give a big chance to win in gambling, instead of having a luck inside is an important tool. We are not players just like in basketball that really be needing hard works but we are playing in casinos which is in a different approach from doing it hard than of playing as a player.