Copyright fuels a weird form of creativity, the “Original Character do not steal” that is a blatant copy of another character. It also happens in music all the time, “Original lyrics, sound and composition, do not copy”
As for promoting free speech, yeah, no, it doesn’t. Everyone can point to a dozen videos being taken down by bogus copyright reasons, whether because it played 10 seconds of a specific music, or because the author of a piece of art disliked the video. That’s not even mentioning how you can’t (couldn’t?) use the “happy birthday” song in USA without being copyright struck.