There’s “formidable” and then there’s “formulaic”. Cameron’s work has been immensely successful in the short term, no doubt, but little of it has much in the way of longevity. Titanic and Terminator, that is really all he has that has proven staying power. For the billions that it made, I hear very, very few people talk about Avatar anymore. He makes big budget, but ultimately disposeable junk. He’ll wind up being a footnote in history, just like all of the authors that outsold Herman Melville back in the 19th.