Insurance is meant to protect you from catastrophic loss. Insuring a cell phone is ridiculous.
Says who? Catastrophic loss coverages are meant to protect you from catastrophic loss. But insurance in general is meant to protect you from whatever contingency the insurance policy is designed for. Why is it ridiculous? It's an ecomonic transaction -- State Farm believes they can make money selling these $30/yr policies and buyers believe that it affords them incremental protection from their perceived risk that is valuable to them.