Text has the benefit of extensibility and loose datatyping - you can encode all sorts of stuff as text, and with a bit of care, extend the "protocol" (human or

Text has the benefit of extensibility and loose datatyping - you can encode all sorts of stuff as text, and with a bit of care, extend the "protocol" (human or machine) in such a way that receivers (current or future) can decode it (with a high degree of precision), even if you hadn't previously agreed on the protocol. You can of course do this with multimedia or any other encoding, but text is pretty great at on-the-fly extensibility.