1)Rishonim tend to ask logical questions and questions based on other texts, NOT questions about why the gemara/other rishonim used word X.
So apparently you don’t learn rishonim.
Endless discussions in Gemara and rishonim center around questions of phraseology.
2) I have a very hard time believing the underlying assumption that the Rishonim are malachim* and every word they wrote contains a chidush. As far as I know, no rishonim thought that there predecessors wrote like this, and nor do rishonim think that the gemara writes like this.
The Ohr Zarua writes how every word of Rashi has meaning, and if one reads carefully they can see that many questions can be resolved by a single word of Rashi. Because, he explains- he wrote with Ruach hakodesh! (or something to the effect of ‘divinely inspired’ – don’t remember exact lashon).
And it goes without saying that regardless how we should learn the seforim, they certainly made a very big deal of diyukim.