There are some movies which one enters into with low expectations, and which one thinks, "Ok I'll just go along for the ride". In such situations, one chooses a relatively inexpensive movie ticket and hopes the ride will be better than expected. There are times when one is pleasantly surprised.
This movie was not one of them, and should signal the death knell of the Monsterverse (though idiot fans like me will still give enough money for them to feel justified to keep making movies).
The first Godzilla was the gripping thriller of the emergence of an unknown beast who killed the protagonist's father and whose leanings are unknown. Godzilla was a hero only because he destroyed the MUTOs. While the movie was a little too dark (lighting wise), Godzilla was done well and the movie felt like an action thriller. Kong: Skull Island was similar, though a little more levity existed. Godzilla: King of Monsters was an all out kaiju battle, but you could see that it was getting less intelligent. Still, the kaijus were amazing to watch. Godzilla vs Kong with the emergence of Mechagodzilla was starting to feel tapped out.
This movie was just not great, and its focus was so mismatched that it didn't feel worth the 115 minutes of its runtime. It discusses a new threat, but the antagonist keeps changing size depending on who was fighting it. It talks about a hidden civilisation under the Hollow Earth but save for some pretty quartz effects is really not dealt with very much? The movie seems to recognise what worked in Godzilla vs Kong and HITS THOSE NOTES TO DEATH - the ironically calm 80s soft rock, the humourous beats by out of water Brian Tyree Henry's character, the swirling camera during the fights.
This is a thoroughly cynical movie that seeks to redo what worked. That means it doesn't.