Sometimes the California Supreme Court grants review in a case that appears to involve purely error-correction. Nothing huge at stake (except to the parties). No real split in the lower courts.
This seems one of those cases.
Do we really care whether it counts as "insurance" for A-1 Self Storage to offer to charge $10/month so that the first $2500 in damages to stored items are covered? Sort of. But probably not sufficiently to justify the time-constrained involvement of the California Supreme Court.
Yet the case is presumably an easy one. It's unanimous.
So I'd guess it didn't take up all that much of the Court's time.