It depends on the game you play, if it's like slots or sportsbook, maybe luck is better than skill. But if it's a game like a board game, maybe skill is more necessary than luck.
However, if you look broadly at gambling, what is really needed most is luck, in any game, luck definitely plays an important role. No matter how good your skills are, if you don't have luck it will be in vain in the end.
I disagree with sportsbook as a luck-reliant game. It's not. I think most bettors on that know the possible outcome of the game. Not 100 percent accurate but they do have an idea of how it will end up by checking stats, and history, or they just know the team or the player that will be playing. Analysis is much needed when it comes to sports betting, just blindly betting could end up in a loss or a lack of knowledge about the preferred game.
Board games, yes, poker especially. That's a skill-based game because even the lowest card or a non-winning card can be a winner using bluffs. But, it's best played physically, I don't really like online poker today even though you can see the players on your screen. There are habits that cannot be stopped which could help out to know if the opponent is bluffing or not.