Trading does not depend on psychology. Gaining profit or loss from trading depends entirely on the experience of the traders. One person has enough knowledge about trading and understands the charts and when trading is likely to be profitable, and another person who has no knowledge or experience in trading trades based on guesswork. Whose money is at risk here? There will be and chances of a person making profit is definitely the first person because the first person is not making a trading decision depending on his own luck, he is using his experience and having an idea about trading and then trading. So trading is never dependent on psychology.
Totally agree with you that trading depends on how much you know about trading. Trading is not just a name for speculation but it requires complete skill and experience. People who have experience and have complete knowledge about the market are generally considered to be successful traders.
It is very important to keep aware of market fluctuations or any coin's support and resistance levels and surrounding news. My own experience is that if you just guess trading without thorough analysis, you will always face losses. An experienced trader's profit rate is always the best.
Knowledge and skill is not enough, they are key but you still need more than that, but what else you may need to become a good trader? And in my opinion the ability to perform under pressure is critical.
A clear example of this happens on sports, there are players which have fantastic skills but when the time comes in which everything is on the line and they have to perform to the best of their abilities they fail at the critical moment, while there are players which have the same level of skill but when faced with such a difficult situation they find a way to win, trading is similar, if you cannot make the right move just when you need it the most then your trading journey will be incredibly hard.