Self-storage facilities are extremely profitable. They generate some of the highest returns per square foot of rental space and are inexpensive to build.
However, from a renters point of view, those metal boxes are expensive.
I understand the need to store items for a short term. Military members that get deployed, temporary jobs, relocating and the need to store excessive property while you search for permanent housing.
BUT, if you're just just storing property that you have accumulated and you will NEVER use it.......that stuff needs needs to go.