Reading exposes you to what's already been done.
The good stuff inspires you. The bad stuff warns you what doesn't work.
Could someone who's never read a single comic, write a good comic? Anything's possible in theory but if I had to bet money on somebody, I'd put it on somebody who's an avid reader every time.
In my own work, whether I'm editing panels or doing rewrites, I can't tell you the number of times I've tapped an 18 year comic reading history and been like, "Oh in this situation, it kind of reminds me of Alan Moore's work on Swamp Thing, Earth to Earth, or "this story resonates as early X-factor" or something...
Not to mention the super obvious, of having someone say, "Hey Xyz, I want to do this story inspired by this comic and this comic."
If your friend doesn’t immerse themselves in comics, they can never tap into that.
Tell them to write on, write often!