I think that the reason magic in fantasy is so language-focused (spell scrolls, spellbooks, magical symbols, ofuda, etc.) is because a lot of our cultural concepts of magic come from a time when literacy rates were very low, and the concept of “someone can draw the state of their mind onto a piece of paper or a stone tablet, and others can interpret those magical symbols and gain that same state of mind” was incredibly foreign and possibly even frightening

and then of course those in power really liked that they were the only ones who could interpret the magic thought-symbols, and as the literacy rate went up they tried to maintain this type of control by learning dead languages like Latin and writing only in those. which is why, for example, the Catholic church relied/relies so heavily on Latin (because the common people can’t understand it - only those who are chosen by the Catholic hierarchy can)

also of course it was in the nobles’ best interests to maintain and expand the culture of “writing is magical and sacred”