If ‘Avatar: The Last Airbender’ had been constructed like ‘RWBY’
This is meant more as a conversation-starting observation than a bitter complaint or even a sincere criticism.
In order to be a criticism, I would need to be convinced this is a problem rather than simply a difference to analyze.
Imagine if Avatar: The Last Airbender had started without Aang
For the first Volume, we're following a group of Waterbenders, Earthbenders, and non-benders as they fight the Fire Nations and also other people from the Earth Kingdom or Water Tribes.
Aang gets introduced in Volume 2 or 3.
And only after that Volume does the story reveal that Aang isn't just the Last Airbender, he's also the Avatar. And only then do the heroes need to take Aang to find all of his bending teachers, Avatar Roku's temple, and that spiritual guru who teaches him how to control the Avatar State.
If RWBY were constructed like Avatar
Our central protagonist would have been the Summer Maiden -- the one Maiden at the start of the story who isn't senile, a traitor, or dead. Presumably.
That’s not to say we wouldn’t have Team RWBY; Aang had Katara and Sokka, after all. The story could have started with Ruby and Yang who then find the Seasonal Maiden who serves as the central hero of the narrative.
And the Summer Maiden might or might not have started out with the Sword of Destruction, the spirit of which may or may not have already clued her into the existence of the gods and their test.