In history, sure, the idea deserves criticism. But in fiction this archetype is called a protagonist and its very different to tell a story without at least one. Is Sherlock Holmes an example of Great Man theory? Most people are not as gifted as he is. What about Robin Hood? I’d argue that these characters share a lot of traits with Batman and Green Arrow respectively, so why is one ok but not the other?
As for the status quo thing, I honestly don’t know what to do about that from a storytelling perspective. “Guy who shoots lasers decides to enact social reform” is an odd pitch.
Are you referring to The Legend of Rah and the Muggles? That was found to be bullshit the second people read the book. It’s an extremely weird story about nuclear fallout, talking animals, and a shit ton of meandering filler. The only similarity was use of the word “muggle”, which doesn’t even mean the same thing in both stories. JK may be a TERF now, but she is not a plagiarist.