2/ Lack of knowledge—Inadequate understanding of the market, trading strategy, financial instruments, and fundamentals can lead to poor decision-making.
Yeah that's part of main problem of some traders they don't wait to get enough knowledge and proper exprences about the trading, they will just jump after into it after they are unaware of the risks that is involved. And that's why they quickly make wrong decisions for themselves.
3/ Not having a mechanical trading system—This leads to emotional trading. Decisions driven by emotions like fear and greed rather than rational analysis result in significant losses.
A trading deserve a lot of things that a person need to get before introducing himself into it, first what you mentioned earlier which is emotional any every traders most have the emotional, secondary patience he most learned how to be patience enough and also know how to control the market strategies if not he will not achieve anything.