Agreed. Origin stories themselves are not the problem. It's just that, with certain characters, we've seen their origins over and over and over again. Everyone and their grandma knows at least the basics of Batman's origins, or Superman's, or Spider-Man's etc. Also after Batman Begins, I never want to see Batman's origins story play out on film again, that movie was such a fantastic representation of it. And then there are other characters who's origins just really aren't interesting enough to take up an entire film.
But there are other characters who's origins either aren't well-known, are really interesting, or both that I COULD see making for good movies. For instance, the first Iron Man movie was essentially an origin film, but I still loved it since they did something new and interesting with it. Wonder Woman, Aquaman, Black Panther, Captain Marvel, Doctor Strange, etc. These are characters with interesting origin stories that I WANT to see play out onscreen.