I think poker has a very high degree of luck involved in the short term (days, weeks and even months). But over the long run (years, decades), there is almost no luck involved at all.
In the long run poker is all skill.
The cream always rises to the top, and the best players always win in the end, because you cannot fight the math over the long run in this game and expect to win.
Playing bad
hands for example. This is something that amateurs often do and it will eventually catch up to you in this game. I actually talk about this in my latest video.