Title text:
You say no human would reply to a forum thread about Tom Bombadil by writing and editing hundreds of words of text, complete with formatting, fancy punctuation, and two separate uses of the word 'delve'. Unfortunately for both of us, you are wrong.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3126/
Information entropy. You need roughly as many syllables to explain the same concept with mono- or disyllabic English words as you do with a scientific polysyllable. Admittedly, some of it is "I know this word! See how smart I am!", but another part is how much more fluid it is to say. "Monosyllabic" rolls off the tongue a lot more easily than "having only one sound".
(The funny answer here would have been "No.")
On top of all that, monosyllabic is accurate to the intended meaning while "having only one sound" is not: a single syllable word often comprises multiple phones and/or phonemes.