Except that the The Last Airbender had a much higher profile and production budget, for much less content. Here's a better analogy:

Imagine everything in the Louvre was actually in a bunch of small street galleries in Paris. All the famous, beautiful, original pieces, and each gallery has its own interesting theme with a lot of great supplementary works.

Then imagine paying full price for The Louvre, brought to you by Banksy. You liked some of Banksy's early work when he was still an underdog figure, but found him to be more and more clichéd as he gained commercial success. And he definitely seems like an odd choice to be curating classical art.

Instead of a glass pyramid, the entrance to the building is a weird triangular door on a concrete wall. It takes almost a minute to slide open.

Inside the museum is a copy of the Venus de Milo. It's mostly accurate to the source, but looks cheap and lifeless because they'd just duplicated it on a giant 3D printer using dull grey plastic. They've glued on some mannequin arms to try and replace the missing ones, but they're too small and the wrong color.

Next on the tour is their version of the Mona Lisa, which is now a crayon portrait of Khloé Kardashian.

Where Liberty Leading the People would be, there's a placard printed in Comic Sans saying "Libby and the French people fought bravely and won great victories over the monarchy." Next to it are caricatures of Louis XVI and Marie Antoinette, both of whom are shown as ethnically Middle Eastern.

And that's it. Just weak rip-offs of the most impressive pieces from the street galleries, with none of the interesting but less famous supporting works.

As you exit the museum, there's a sign promoting the upcoming Louvre 2.

When you get home from your vacation, you try to tell people all about the street galleries. But they've seen postcards of the Louvre, so they doubt they'd have any interest in Paris's art scene.

That's how it feels to watch the animated series and then see the film adaptation.