Just watched this video on hags in D&D which have been one of my favorite monsters since I read Van Richten's Guide to Hags & Witches for Ravenloft way back in 2E. It's a pretty good video!
So the interesting thing about hags to me is that they aren't just wicked witches, they're supernatural, almost elemental beings. Hags in real-world legends like Peg Powler, Jenny Greenteeth, Black Annis, even as far back as the three Gray Sisters from the myth of Perseus are thought to be vague memories of an older generation of goddesses tied closely to nature. You can see that with the three main hag types from the Monster Manual - green, sea, and annis - who are strongly associated with forests, oceans, and mountains respectively. There's a sense of them having dwindled from a more powerful state, and I think a GM can use that can generate a powerful sense of sadness that makes them more than hungry monsters.