I think there are both, but for me it is more skill than luck, of course in the short term luck will always influence more, but in the long term skill comes to the fore, since you can be lucky in a tournament or in a cash game and win, but if you don't have skill you will only lose more times than you will win. To have the ability you must investigate, study, update yourself and put into practice everything you have learned, there are people who are born to be winners in everything they do, but the vast majority are winners for their research, studies and putting into practice everything they have learned, to to become good at something, it must be done out of interest and conscientiously and not as a hobby.