The first 5 minutes of this video do good job of explaining what i'm getting at - https://www.youtube.com/watch?v=YNJDH0eogAw
You would also think emphasizing grammar's usefulness would make it plain that I do not think it is a waste of time.
My German is pretty rusty, why exactly is it unambiguous?
I don't see how changing the noun would make a difference. "Ich sehe" followed by any of these: "den Mann mit dem Fernglas", "die Frau mit dem Fernglas", "das Mädchen mit dem Fernglas" sounds equally ambiguous to me.
In my view, this phrase is only unambiguous to those who feel the preposition tradition, and all the heavy lifting is done here by “mit” (and “durch” in the opposite case, if one wants to make it clear). Articles are irrelevant and are dictated by the verb and the preposition, whose requirements are sort of arbitrary (sehen Akk., mit Dat.) and fixed. There’s no article-controlled variation that could change meaning, to my knowkedge it would be simply incorrect.
I’m also quite rusty on Deutsch, aber habe es nicht völlig vergessen, it seems.