You need luck in trading also. Remember the leverage platforms which pay to 10x-100x leverage amount and you have to guess the right movement of bitcoin. I think luck plays a major part there too but people think that they have skills and therefore they did a successful trade, which is not the actual reality.
I totally disagree, luck is not included in trading.
Trading is not as simple as you have to guess the price movement, traders have the knowledge and capability to read the market price movement base on their experience. They don't base their possible profit on luck, because every time they trade they already have their expectations.