Just an assumption, but yes. It’s a crystal, and it forms in deposits. Most crystals are found in the ground or in caves.
I believe that it’s the most popular method for obtaining salt, but it’s also dangerous because of caves collapsing.
It’s probably the best way to go about it also because in other methods they would probably have to develop some type of mechanism that makes it rise and that’s too time consuming. Hope I helped in some way?? Lol