I was quite surprised when I first had to handle large amounts of cash. Securely transporting it to and from a bank is quite a hassle, and making sure you always have enough change is as well. Idk about the specific economics of it, but it’s easy to underestimate for those of us who don’t have to deal with it at scale.
A covered space is easier to keep warm. Also the crater hole might well have let in rain that could be blown around by wind.