Godzila is not a superhero. I never saw a full Godzila movie, but I know that there are a lot of movies where Godzila destroy Tokio. Let's take for example the latest Godzila movie: the first movie from the Monsterverse, the same universe with Kong: Skull Island. I didn't watched the movie, but from the internet I ended up to consider that Godzila is a threat. Let's take another example: the future Godzila movie, Godzila: King of Monsters. I don't know anything about this movie, but I know that there will be more classic Kaijus that will try to destroy the city. And also, don't forget Godzila vs. King Kong. _Why would King Kong fight Godzila if it wasn't a threat.
But you may be right. There are tons of old and weird Godzila movies out there, with Godzila saving the day.