I suppose that wenyan is not a normal spoken language [1], but a form of a literary encoding, more like poetry meeting stenography, and a way to crystallize the meaning without excessive syntax.
English translation requires many more words because a "normal", vernacular Chinese rendition would also require many more words.
My suggestion is to assume quotes:
"Dao which is 'dao' is not true dao", that is, the mere word "dao" (and, by extension, any more descriptive and explanatory words) is insufficient to convey the meaning of true dao.
Well, probably not, no -- I'm pretty sure the Daodejing was written in a literary language quite distinct from any spoken language at that time. This used to be something readily found all over the world.
English translation requires many more words because a "normal", vernacular Chinese rendition would also require many more words.
My suggestion is to assume quotes:
"Dao which is 'dao' is not true dao", that is, the mere word "dao" (and, by extension, any more descriptive and explanatory words) is insufficient to convey the meaning of true dao.
[1]: https://en.m.wikipedia.org/wiki/Classical_Chinese#Grammar_an...