The movies have essentially turned Ron into nothing more than a generic sidekick.
It's natural to think that Ron is pretty useless as a member of the Golden Trio if you've only seen the Harry Potter movies and never read the books. According to fans, the movies did not do justice to Ron's character, while in the books, not only is his role in the Golden Trio much more prominent, but it is also clear why the Sorting Hat deemed him a Gryffindor.
"They turned him into a generic sidekick with almost no real importance beyond occasional comedy relief," Redditor shaodyn said.
Other fans have largely agreed with this sentiment, noting that Ron might as well "not even be there 75% of the time," or even suggesting that the movies "were better off making Harry and Hermione a duo than keeping Ron for the trio.
For some reason, the filmmakers even went so far as to give Hermione Ron's best lines, which turned out to be detrimental to both characters. Remember the time in the Prisoner of Azkaban movie when Hermione stands in front of her friends and yells, "If you want to kill Harry, you'll have to kill us, too"? Well, that was actually Ron's line in the books.
"In the book, his leg was broken and he stood up on it anyway and delivered the line without any trace of fear. He even repeats it ("did you hear me? You'll have to kill all 3 of us!")", Redditor cshelley0721 recalled.
Another fan added that "not only did this remove Ron's complexity and make him one dimensional", but it undermined Hermione's complexity as well.
"In the books she's actually much more flawed and annoying," Redditor Banana-Carnage noted, quickly adding "in a way that's endearing and entirely human, of course."
According to fans, "the movies did Ron dirty," especially since most of Ron's annoying qualities were carefully preserved for the screen. In Goblet of Fire, he treats his friends badly; in Deathly Hallows, he leaves Harry and Hermione in the woods in the middle of their Horcrux hunt. However, many of his truly heroic moments were left out of the films.
To be fair, film adaptations rarely end up being as good as the original, so the Harry Potter film saga surprised no one when it failed to live up to the books.