Well, in my opinion, I think that gambling depends on luck no matter the game. Skill based game like sports (soccer for example) also depends on luck, I have seen someone that staked a very huge amount, I can not be precise about the amount but I guess it was close to $1k, the man stake the amount on two games, one was just 1.1 odd and the second was 1.3 odd but he lost the bet. Normally, the prediction was perfect but the outcome of the game was just unexpected. The skill game like poker also depends on luck, because you can not be very certain about the outcome. One can get disappointed in gambling on the game they attached all their hope to.
Take luck out of gambling and what you have left is nothing and Gambling will become nonexistent since the gambler winning depends on luck so if the factors for winning is off, it then means that the business for both the gambler and the casino is overs since no gambler will want to keep gambling when he sure that he will not win, because winning in gambling is 90% based on luck so without luck you are just 10% lucked in with whatever skills you think you have developed over the time, and one other challenge for skills based in games is that, not all games you have developed the skills to beat the house on, and even in football betting, there is still the possibility of failing at your team analysis and at some point depends on luck to ever win at those games.
I still remember the last bet I took was around 1.25 odds and on football live game, and when I staked 0.0001 bitcoin I was high hoped to win based on my team's analysis, but since the luck was not on my side, I still ended up losing that bet and then I realised that luck is a vital factors in Gambling and we shouldn't expect so much based on skills.