Technically they need some moisture, at intervals, my cloner only sprays water on the stems for 5 minutes every hour for 22 hours then nothing for 2 hours and then starts again. So the majority of the time the stems are just moist and able to get air. If the soil is soaking all the time, the plant won’t bother to waste energy making roots, when it can suck it straight up the stem, any time it wants a drink.
You have to force them to do it, with wet and damp cycles which allows the roots to get air as well as water once they start to develop. Remember they will take the humidity through their leaves which is why you need a humid environment.
The bacteria/fungi that cause damping off are always present, you just have to not give them the perfect environment to thrive in. Which is wet and cool.