Didn't really see this idea, but imagine adding areas in the deep caves, amongst the grimstone and deep dark where there is no bedrock , just bottomless area open to the void. There could be some sort of traps involving gravel or other block that would give way and drop you out of site into the blackness if you weren't careful. Some of these bottomless pits could also end up in the overworld in certain biomes like a jungle or a mesa biome. They would be like mineshafts that if you mistepped and fell into them you would fall all the way to the void unless you thought fast and had some kind of tool to save you. A grappling hook could be deployed to stop your fall into the darkness or an ender pearl, possibly a levitation potion?