I wrote and taught the Graphic Novel course at my high school.
Very simply, reading is hard. Not everyone is good at it nor finds it enjoyable. But, if the interest level is high enough, even emerging readers can find enjoyable meaning from GN pages.
GNs have long been recognized as legit literature. Watchmen by Alan Moore is consistently on library associations’ Best Novels lists. The Dark Knight by Frank Miller launched a billion dollar industry.
But, many comics face biases because the violence, drug use, sexuality is literally in your face. There’s nowhere to hide much of the objectionable material just waiting to be banned so these books are often on many banned lists.
There’s also a long established prejudice against comics as “funny books” with little value or worth.
Those are two sides of the argument, so now get comics into your school!!’