The biggest mistake that day traders make (especially crypto day traders) is believing that they have an edge over everyone else because of the charts they look at. The biggest mistake is not believing that day trading is 100% gambling, because that is exactly what it is. The only way to consistently make money over the long term is to invest based on value and fundamentals.
Exactly, I usually consider day traders as gamblers whom have decided to take massive everyday risk. With the unstable price of bitcoin, I do wonder how they make their gain; though some traders claims it very gainful. Its takes one with huge capital and heart hardened to become a day trading. Because for me alone, bitcoin trading is a perfect risk on it own. I most times soley depend on long time investment.
You don't have to necessarily day trade with your whole capital, and if you do, then I would most certainly agree with you. On the other hand, if you set a small percentage of your deposit for day trading, you take the opportunity of both short-term volatility and long-term trends. This topic is likely worth a separate discussion of its own. For now, I can just say that it is definitely a profitable strategy if you know how to properly handle it. Besides, day trading also includes arbitrage and it can be quite profitable as well if done right. I hope you won't call arbitrage gambling.