Regarding that Black Panther/Pixie example from answer to other person’s question - doesn’t that mean that the best chance fans have to see more of their favorite characters is if they get a jab at Marvel and start writing them themselves?

Sometimes maybe. You certainly need somebody that loves and is interested in a character like Pixie to want to put her back front and center. And a character like the Black Panther has a 40 year head start on her, which means generations of potential fans-turned-pros who loved that character when they were readers.