This is precisely it. Avatar had originally the exact same problem that the Way of the Water has now. They're tech demos. Interesting, pretty, they move people to see what's what on the theater. But, offer close to nothing emotionally or culturally resonant. It's like a generic roller-coaster, you show up, enjoy the ride, then go get some fries having nothing deeper to say about the experience because the experience doesn't offer anything deep. It doesn't mean the movies are bad or that they weren't enjoyable, that's why they made so much money. But there's no conversation to have around them except to remark on how much they cost to make, or how did the CGI looked like or whether other studios will use the tech invented for this movie on other movies. Plot, characters and symbolism are shallow pools. Specially to an audience that is sick and tired of mega blockbuster sequels.