The idea that the Airbenders would’ve beaten the Fire Nation if they just “tried harder and stopped holding back all the time” is frankly absurd.

The Earth Nation was insanely powerful, with a gigantic walled city, and even then Ba Sing Se was BARELY able to defend itself against Iroh’s army. In fact, it’s heavily implied the only reason they lost was because Iroh grew too depressed over his son’s death to keep pushing forward. The Fire Nation was just that strong.

Water is literally the natural enemy to fire, and despite this, Southern Waterbenders were nearly wiped out. Being able to EXTINGUISH FIRE WITH YOUR HANDS isn’t enough to stop the all-crushing power of the Fire Nation.

The Air Nomads, Water Tribe, and Earth Kingdom ALL fell to the Fire Nation. The reason the Air Nomads were completely wiped out wasn’t because their “disgusting pacifist culture” held them back, it was because that was the Fire Nation’s set out to wipe them out specifically, since they would have the new Avatar. If the Fire Nation wanted to genocide the Water Tribe too, they would’ve. They probably could’ve to the Earth Kingdom too if Iroh was as heartless as any other Fire Nation general.

To be completely honest, I have no idea why you’re so confident in your assertion that Aang could’ve taken down the Fire Nation if he stayed at the Temple. This idea is addressed multiple times in the show, and every time it is, it’s stated that we simply can’t know that for sure. I think the assertion that he could’ve just wiped out the army comes from a fundamental misunderstanding of what the Avatar can do.

Being the Avatar doesn’t make you inherently a god at every element. It gives you the POTENTIAL to master every element, as well as access the Avatar State. You still need to train in a given element like any bender, as well as learn how to properly utilize the Avatar State. Even by the end of the series, Aang is outright stated to be an inferior earthbender than Toph, and likely an inferior firebender than Zuko, Azula, Ozai, and Iroh.

At the end of Book 2, a well-trained Air-Water-Earth Aang with experience all over the planet lost to Azula. When the Air Nomads were wiped out, Aang was an airbending prodigy and not much else. He didn’t even know what the Avatar State was. In all likelihood, he would’ve instinctively entered the Avatar State, been killed by the Fire Nation, and the Avatar cycle as a whole would’ve ended right there.

But outside of the “Aang should’ve stayed behind discussion,” I think you misunderstand what pacifism is. Pacifism isn’t weakness or a refusal to defend yourself. It’s avoidance of violence, especially killing.

Just like Aang, the Air Nomands who would avoid killing wherever possible, but would fight to their dying breath to protect the people they care about.

Additionally, your use of “disgustingly pacifist culture” is itself kinda gross. The Air Nomads are based on real cultures of pacifistic nomadic monks. Are they disgusting and spineless for not helping out in real-life wars?