similar to shaanbei yaodong are the cave houses in the sierra nevada in andalucia. especially the sacromonte caves in granada, traditionally inhabited by roma who were not allowed to live inside city limits
Digging out a ton of rock and earth is a lot more complicated IRL than it is in games like Dwarf Fortress or Minecraft. Real life geology is pretty complicated, you gotta deal with shit like ground water, unstable types of earth, blasting. It's all pretty expensive and dangerous. Meanwhile humans have gotten pretty good at erecting shit above ground, we can throw up sheds and huts like nobodies business.
Edit: Also plumbing, electrical, HVAC, means of egress and sewage become problems with subterranean development. Digging a room underground, doable, but then you're gonna have to dig out additional shit to get all the water pipes and air ducts in there. Also, people like having windows, and windows are good for fire safety, but it's kind of hard to put enough windows in if only one side of a dwelling is facing the open land.
it's a dangerous world to live in. just the other day i built a well over an underground lake in a cavern layer. every now and then a giant bat would fly up the well and into the room, flap around a bit, and then leave back down the well. but then one time one of the children was in the room and in a panic running away from the giant bat ended up falling down the well and drowning.
Keeping the water out winds up being a huge problem. Either its percolating down from outside water sources and working down through the cracks in the rocks until its inside your house or its condensation buildup from the living things inside the cave house.
Personally, I'd love to live in an underground bunker because I'm a weirdo, but i would be pretty cool with some small single story house with a reinforced shed style roof with a few feet of soil and let the crass grow.
It would be so cool to have a stairway with glass in one side so you can walk up or down the stairs and see the change between above and below the waterline
This is tangentially relevant, but in my conworld I'm mainly writing about one specific country, and this country was colonized by a foreign empire. A major part of the colonial resource extraction was in the form of mining, particularly open-pit mining. When economic crises led to a lot of mining companies pulling out of the colony and simply abandoning their old mines — with these crises also leading to widespread homelessness within the colony — a lot of homeless residents actually ended up carving homes into the sides of the benches of the abandoned mining pits. A lot of these homes are still around today, albeit less hazardous and with running water — and the people who live in these homes are called "troglodytes" or "trogs" or "troggies".
Homes are mostly empty space, gotta move more stuff to empty them out than to move the walls into place.
If you're building your house above ground, you know exactly what's in the way (bunch of air). If you're building underground, you have to deal with a bunch of different kinds of ground, and you don't fully know which ones where until you start digging.
I would like to live in a subterranean quonset hut or earthship. I also would love to just build a home inside of a mountain, though this is probably due to my inspiration from Minecraft, lol. My heart yearns to be a commie dwarf.
You can carve dwellings into the sides of mountains or hills. If it's stone you're digging through, it takes more effort, and if it's soil, you have to worry about groundwater and internal supports. As long as all the water and condensation will drain around it and also out of it, it can work. Also, you do want sunlight, so there's a bit of a limit to how deep you want to go. You could put storage in the interior, but without the light and air exchange, it wouldn't be very suitable for regular living space.