I think parent is referring here to the fact that math used to be written without symbols (other than numbers) up to the 1300s according to Wikipedia: https://en.wikipedia.org/wiki/History_of_mathematical_notati... (very interesting article!) However, I would say that there is a reason why notation tends towards terse symbols: it's much more efficient and unambiguous.

Even Newton's Principia has symbols, they're just different. His notation used dots and lines & boxes in various positions.[1]

[1] https://en.wikipedia.org/wiki/Notation_for_differentiation#N...

Maybe ctoth or some other user of screen reader might have a look at https://en.wikisource.org/wiki/The_Mathematical_Principles_o... and tell us how it goes.