Stop loss very important for daily trader so they can manage their risk and did not lose all tgeir money in one trade. They also usualy did not hold or doing swing trade. Time is very important for daily trader thats why they use stop lost if there are mistake in their prediction.
Or if there's a sudden market swing and dump that they didn't expect. That's why stop loss is a feature that helps everyone to avoid huge losses which have been happening for so many traders. They're forgetting to use this feature so that when their trade goes wrong, they would only have around 1%-5% of losses. And that's the percentage that most of the traders do and sometimes there's also a stop loss of 10%, depending on how much the trader sets it.