It's quite understanding how day trading could work better than holding, but trust me, some very volatile coins doesnt support that to some extent, I recently tried day trading on a coin. I sold the initial when price was high, then bought back the tokens, had more. Then greed made me sell again when price went up, only that this time, it kept going up for 1 month plus and that's how I couldn't buy back.
So in essence, volatility matters