There's a lot going against the reception of the video game (biggest being it's a video game based on a movie). There was a lot going FOR the Cirque show (biggest being it was Cirque).
The world has changed drastically since 2009, but Americans still only see an average of 4 movies a year. With the ubiquity of streaming there's less NEED to see movies that aren't established as "must sees." And for almost a decade, Avatar has been known as the pretty film with no original ideas. And the wait for the sequels has made the absence of story, and the lack of sustained relevance farcical. I mean, the Avatar jokes in Bill and Ted worked because the franchise has almost become a joke.
Zoolander 2 might be our best comparison for how Avatar 2 will be received.