What happens if Avatar: Fire and Ash doesn’t make enough profit to convince Disney to bankroll Avatar 4 and 5? Creator James Cameron has said he’s ready to walk away from the franchise, adding he’ll write a book to resolve the one thread Avatar 3 leaves open.
The first doesn’t really (and the thread they “re-opened” to connect the sequel is pretty bad), but the second one does leave a couple things open.
In general, the second one does improve a bit on the criticisms of the first movie. Not enough to make it great or special IMO, but at least it’s a bit better.