I don抰 know a single trader who doesn抰 use a stop loss order. It抯 a fundamental risk management tool that I think everybody should use in order to prevent excessive risk towards their trading balance. It may play out for you, but only shortly, because there are so many moments in trading when you open a trade and it goes against you in a few seconds. I remember entering a trade and it just tanked right away because of the sudden Trump tweet.
And you know what? I set my TP and SL orders before entering, but still, the slippage was crazy and I had a big loss that day. As you can understand, there are scenarios you can抰 control, and stop loss helps you to stay guarded.
On the other hand, if you are an investor and buy quality stocks & indices for years probably you wouldn抰 need to use stop loss. Those assets don抰 drop 50% in a day, it抯 very unlikely.