The second Godzilla movie that ever came out, less than a year after the original, ditched nuclear allegory for a story about working men trying to keep going in the face of disaster. The next Godzilla movie after that was a parody of the salaryman comedy and kaiju films as a whole. It was like if they dropped Space Balls as an actual sequel to Star Wars. The film after that was a crime thriller about an international assassination plot.
Why is America held accountable for not having constant nuclear allegory when Japan didn't bother with it for 90% of the franchise? Worthless larpers.