Avatar 2 topic (spoilers)

I saw this a few days ago, just a regular showing. Havent seen the original in a number of years, so all I remembered were the general story beats.

I enjoyed the sequel quite a bit. I was invested and found the world building to be interesting. In particular, the whale hunting scene was really well done. Then I kind of soured on it a bit with the ending parts, where it devolved, as these big budget movies tend to do, into a prolonged action sequence where lots of throwaway characters die because violence is an easy sell. Someone, please explain to me why they didnt just dive and swim beneath the burning surface?!? No, instead lets go back to the sinking ship. Where did the Chief of the seater Navi go? Where did his son go? It didnt ruin the movie, but it certainly didnt stick the landing either.