It's mind-boggling to see the sloppiness of the writing of the live-action remake like no one reviewed the scripts and did a second edit. Even separating it from the original series and judging it by its own merits, for a $120 million budget ($15 million an episode), it seems like the writing was the least focused and half-assed part of the production.

There are so many examples, but the first and last scenes highlight this well:

Literally in the first scene, the comet is already in the sky, an Earth Kingdom spy is shown trying to escape the Fire Nation capital, followed by telling a comrade to send a warning of an impending FN attack.

How did the EK know to send a spy? Maybe you can argue that the FN lured the spy, but as you'll see the writers didn't think this deep.

The comet is already in the sky, how can the warning be sent across hundreds, if not thousands, of kilometers so quickly?

Military troop mobilization takes so much time. Troop movement, communication, etc. How can this be done in such a short time?

Remember, the comet is already in the sky. No comet lasts more than a few hours passing by a planet. Unless told otherwise, we have to assume it works the same as in our world.

(The Air Nomads talk about the Great Comet Festival, remember this for later since this and Sozen preparing for an attack means they know when the comet is passing through the planet.)

Sozen, shown at the FN capital, says the attack plan being delivered to the EK is a distraction, and later we see him lead the FN genocide attack on the Air Nomads.

This is heavily implied to not be in FN territory, hence the need for a distraction. Fair enough, the fewer EK troops there, the better. However, how were Sozen and his troops able to travel so far, so quickly? Especially with the comet still in the sky.

In the last part of the last episode, Zhao's attack on the Northern Water Tribe is a failure. However, Ozai is unfazed when informed of the defeat and says the attack on the NWT was merely a distraction and wasn't the true objective (which is Omashu via an attack from Azula). A distraction for who!? At no point did we see or hear EK troops redistricting troops to the NWT, there was no discussion of NWT soldiers going to the EK at any point, and the Aang and the Gaang never said at any point they'd stay in or go back to Omashu.

Hundreds of FN navy ships were destroyed and likely tens of thousands of troops were killed in the NWT invasion. Whereas the fall of Omashu shows maybe 100 troops at the very most when Azula does a war cry celebrating the city's fall. Why and how did Omashu fall? Nothing changed Omashu's circumstances and defenses. They've been able to defend themselves against the FN for 100 years, no EK troops left Omashu to go to the NWT or was there any indication anything changed. There wasn't a distraction from anything.

In the post-credit scene, a FN scientist/astronomist says that celestial studies have been privative and have been catching up. They show the comet's path, implying that now they know the comet will return. Wait, how was Sozen able to prepare and mobilize troops for the Air Nomad genocide? The Air Nomads all came to one location for the Great Comet Festival. This means they know when the comet arrives. Sozen clearly knows this, otherwise, how would he know to focus his attack on that specific temple?

This means that 100 years ago, they could predict when the comet would pass by next. The FN scientist saying astronomy is primitive doesn't make any sense.

There are so many instances of such sloppy and bad writing, it's mind-boggling.

Sorry, rant over. It's disappointing that for a $120 million budget, it's so sloppy and half-assed, even on its own merits.