By comparison, Godzilla: Kong of the Monsters is a very different movie, where everything is much more exaggerated, where secret government organizations are flying experimental aircraft around the world while chasing after massive kaiju.
It’s certainly true that the first Godzilla has a realism that the rest of the franchise does not.
It’s a much more human story about the impact that these massive creatures are having on people.
You can’t really combine these two ideas together into anything that isn’t going to clash, but it at least gives you the ability to see the two different takes and figure out which direction you want your movie to go.