The Orville is basically Voyager. Light scifi trying to be TNG. Only airing in an era where that's considered a good thing.
The original Star Trek is basically Forbidden Planet. Was that a bad thing? And all the Star Trek series are every bit as much "light sci-fi" as The Orville is, including Star Trek: Discovery. A fake Klingon boob and the word "fuck" doesn't make it some kind of serious hard sci-fi.
The Orville is fun and uplifting, in a way sci-fi on TV hasn't been in a really long time. It really doesn't matter to me if it is a copy of Star Trek or not. It has definitely beaten Discovery at being Star Trek.