Attaching pictures, being able to review the content for accuracy/completeness before sending it, being able to pause and do something else in the middle, B/CCing others, and having a copy of the sent document for the record are all pretty helpful. The reason I'd forgo those benefits and call is if I thought I was going to be able to talk to a human right now and just get it done without a to-and-fro.

For example, calling 0800-TEXT-HN and narrating this comment back-and-forth to an machine would be pretty nutty.