I have a document that has 1.8" left and right margins allowing me to adhere to the 65-75 characters per line rule which is considered to be the optimal line length for the human eye to scan. Leslie Lamport, the creator LaTeX, mentions it on this page: https://haroldpboas.gitlab.io/courses/math696/LaTeX-customizing-page-layout.html
My document uses the Charis SIL font at 11pt which is nearly the same size as the
"Times New Roman" at 12pt. Perhaphs the Charis SIL is a notch smaller but the added legibility of the Charis compensates nicely for the size difference.
The problem is that the left and right margins are large on A4 paper.