dont know about the anime but I think the manga does a good job of showing that the grandma reader is really unfair in how she reads. The first time we see her they even emphasize that most top readers intentionally dont do it her way because they dont want to give an unfair advantage but she just doesnt care. That's why the Meijin likes her, she gives him an advantage. Same with Rion, Chihaya, and in part the other teammate who admires her. It is definitely not a mark of quality but a thing that separates her from most other top level readers. It makes it nicer to listen to but gives a big advantage to certain players. ---
"Hope is allowed to be stupid, unwise, and naive." ~Sir Chris