Manual trading without a sl is risky but it really depends on your strategy and wallet size. If you have a large wallet and can dca on large swings then a stop loss is not so important. But if your wallet size is small and you are using large limits then having a sl can save you in that moment when things don’t go as planned.
There are many traders that never use SL for a reason that they want to have the gain in full without selling it in lost. To do that perfectly you need to have experience in trading and 100% sure that your entry is right and will not going to dip more or there are reversal that will happen sooner. For margin and futures trading then stop lost is really important if you don't want to be liquidated.