Maybe that's true, but they can also make more loss than those who are holding. If you are someone that just wants to hodl, you can buy at the lowest price and wait for the price to reach its highest and when it does you will be making lots of profit. In day trading you're making your profit/loss daily, but in hodl you will need to have a lot of patience and wait till the price goes up before you have your profit.

If you can't have patience you won't be able to make any profit. Take for example, if there is someone that bought Bitcoin earlier this year at the rate of $3300 and today price has gotten to $10806, that means you just made a profit of extra $7506 in just few months. Both trading and hodl works, you just have to choose what will be easy for you to do.