It’s not about the story, it’s about the sfx.

Watch James Cameron’s movies like the abyss, Terminator2 and Titanic. (There’s others as well if you want to put in more effort)

He’s a visionary director and I just mean his own vision, Avatar was an idea he wanted to see on screen but was unhappy with the technology until he felt it was ready to tell the idea he had.

Like some other things, by today’s standards everyone else who saw what he did have been able to refine and expand on what he did so it may seem in unremarkable, but he finally decided to do the biggie when he felt the tech had come far enough for him to do his vision and it made Bank. So. Much. Bank

Again not because it’s an amazing original story, comparisons to fern gully were immediate even when it was new, but it was something that sits in a divide of how sfx can be used to tell a story in a way that people hadn’t otherwise shown. Even with a really unremarkable plot