> No it doesn't. Try a plain text description of an electronic circuit vs a circuit diagram.

I'm not an EE, but there's SPICE for regular electronic circuits and SysVerilog et al for logic circuits. Math can be typeset in LaTeX, though its plain text readability depends on the formula. Category theory diagrams can be written in a simple language. Sheet music is some sort of XML, though I imagine there could be a more human writable/readable plain text format for this too. There was also a recent post about Markdown diagrams. And of course, code is still entirely text.

Much of what you mentioned can be described in a concise, portable text-based language. Though these documents are readable as text, they can be further rendered for best readability. Luckily, many can also be live previewed.