If they don't have good risk management and capital management, trading is simply not for them but to succeed with trading, they need more than that. Other requirements like knowledge about fundamentals, technical indicators for trading, good discipline to do well in both risk and capital management, and enough experience in the market. Maybe more and if a trader lack of many of these things, it's more like gambling, like you said, than trading.
Even if you have all the necessary elements to be called a professional trader, there is no guarantee that you will make a profit from trading or that making a profit from trading is easy . Because even if you use all the knowledge and skills you have, you will never be able to predict unexpected factors, or manipulate...Therefore, there will always be certain risks in trading and making profits from it is not easy .
Bitcoin is unpredictable because there are always unexpected impacts, events, or shark manipulation in the short term. Therefore, to minimize the risks from those things for ourselves, long-term holding will be a much better choice.