At the risk of opening this up in a serious direction.....and that’s a dramatic shift from my giant earwig post.....hags and witches generally are pretty deep-rooted in Western culture, and therefore carry a shudder factor for many of us, making them perfect villains.
Baba Yaga in Russia is the obvious example of the terror power of the witch/hag, and Hansel & Gretel gives us another example.
This fear of witches was later heavily exploited in the UK by the likes of Matthew Hopkins, Witchfinder General, and in the US in the Salem Trials about 50 years later. In both cases, religious bigotry and misogyny combined to horrifying effect, as well as simple greed on the parts of men like Hopkins and Mather who made good money out of it.
So hags play on significant levels of historians cultural fear, as well as an array of human ( particularly male) failings. They make great D&D foes too, with or without earwigs!
PS I’m conscious that my brief comments on the role of hags and witches is very US/Euro-centric. This is due to personal lack of knowledge of witches in other cultural traditions. I would be interested to learn more if anyone has expertise.