They sometimes do this because they're certain they have a large amount of capital meaning they have enough capital to bet so they don't think about stop-loss. This isn't possible for those with very limited capital so they always manage their trading carefully and don't fully invest their resources because they know that if they do they won't be able to handle a loss. This is different from those who sometimes have a strong enough grip that they don't even think about stop-loss. They will fully invest within their limits. Ultimately they just wait to see what will happen to their trading bets whether it's the risk or the profit.
This is what some people will not understand, according to some explanation, stop loss is not necessary if the trader knows what he is going. Even if trading with low capital like $200 and expecting a profit like $1 or $2 daily, that is still a good way stop loss may not be necessary. But it is good for a trader to have the right calculations before trading without using stop loss. Stop loss can be good for the traders that like to risk amount of money and also for those using high leverage
It's more accurate, as you said, that traders must make calculations so that this can benefit them in carrying out their activities, especially since some of them like to take risks. I think it's necessary for them to implement a stop-loss.
However, I believe that sometimes not everyone can do it this way because some of them don't like taking risks in their activities. This sometimes leaves them confused, and ultimately they prefer to remain silent without carrying out what they had planned based on their desires before starting.