I dont believe that only luck will favor you all the time. if so then I should say that luckiest people should also be the wealthiest people in the world, but nothing is like that. It means that gambling doesnt depend only on luck and some other factors also necessary in gambling, like gambling skills, tactics, bluffing, tricks etc. having these qualities you will be a successful gambler.
It is also important for gamblers to have a strategy, a tactics, a skills, that is obvious they can do tricks and bluffs that is usual for gamblers since it is a great and oldest trick in the book especially poker which is quite popular.
Even so, even with skills, experience and strategies that you've done, if you are not that lucky, you might not be that successful there. Luck is a huge factor on gambling and let's be honest, that is the reason why there is such things as a beginner's luck. Even without any gambling experience, skill and strategies, with beginner's luck, you can win against great gamblers.