This assumes there is an underlying reality to which descriptions and conceptions can be more or less accurately fixed.
Just enough for you and I to trust your life on it several times a day. E.g. instructions for use, a guide to a dangerous place or a descriptive list of toxic mushrooms. Were it not for its partial but practically sufficient ability to represent some "reality" I doubt language would have developed at all.
But I agree with you (although nvr seems to blame me for that) that it is impossible to assess one system of representations over another globally. We can only compare local or partial differences, zones of "light" and "obscurity," relative gains and losses, nothing more.
Partiality (with its arbitrary separations, obscurities and exclusions) is essential to language. A perfect description of anything would be the thing itself (as in the Buddha's silent "sermon of the rose"), and it wouldn't be a description at all. And since no "thing" can be separated from "another" except by the arbitrariness of language, it would ultimately be the universe itself (like the Borgesian map) -- minus the artificial word and notion of "universe".
My immediate "agenda" is that I've got to write something on the topic of "exorcism" and I feel like airing a few thoughts and questions (lol). More generally, I do obscurely believe in the value of reflection on language and "reality" as a potentially liberating tool (if only for the next kind of servitude). My underlying question being (and it is indeed "political" in the broadest sense), to what has a society which considers itself "free" from "alienating" influences (such as represented by traditional "spirits") actually got itself enslaved thereby? (Syntax uncertain, sorry )