Pretty much the combination of both. Luck can be useless if it isnt executed properly,. Example for poker, if you always have a good card in hand (consider it lucky) , but wont be able to win, therefore you need strategy.
There could be a lot more than just luck and strategy in gambling, you will just be overwhelmed what gambling could bring you. Might make you rich (less possibility I guess) , It might also make you poor (very high possibility, depends on the level of addiction.)
I really think the strategy you are talking about could only apply to poker and all strategic platform games so it will surely depend on the games you are playing, While if you are playing Plinko, Slot, Roulette, etc... this kind of games are all luck Base games that would not simply apply any skills or strategy, Well you can surely put a little strategy or pattern when you play this kind of games it is up to you but if you are surely not lucky on that day then I think you can not see a potential earning,
So There is a high probability that many people would not end up rich if you are expecting that outcome.
And sports betting as well. Your strategy and analysis would be highly challenged when placing your bets and beating the odds. Neverthless, I agree with those you have mentioned that doesnt really need complex strategy when betting.
I'm a supporter that is the combination of both, well, it's game, you have to be clever, full of strategies, because you can have or have deciphered the best strategy of all, but if luck does not go with you, there's nothing to do.
The intuition that you have in the game is another factor that influences a lot, that is why there are many people who play little and earn a lot! Normally some think it's talent, I would call it a great intuition and apart accompanied by luck and strategy. At some point the game will come against us, that's where the strategy comes in, but with wisdom, I'm not one of those who support compound interest, I think that's the biggest failure that can occur.