Aragorn's assertiveness

[Zigûr]

Originally Posted by Faramir Jones

No explanation is given for why she is dying, and if it's Sauron's fault why others aren't also dying.

Yes. Not only is it an incredibly lazy piece of storytelling, because it ups the stakes without giving any reason for why it is happening, it's also pointless; the average viewer wouldn't care - they already know that the heroes have to destroy the Ring and stop Sauron from taking over Middle-earth for reasons that have already been clearly established. The addition of this plot point adds nothing whatsoever to the narrative, even to the altered version of Aragorn's character arc invented for the film.

It reminds me of how in the film Pippin has to have a vision of Minas Tirith in the palantír for Gandalf to realise that Sauron is going to strike there next, and he reacts as if he'd never even thought of it as a possibility.

All Gandalf needs to do is say something like "We may have defeated Saruman, but Sauron is sure to strike next against Minas Tirith, the capital city of Gondor, his old enemy." Anyone watching knows that "Gondor" is a country where good Men live; it gets mentioned a lot in the films. There's no need for Pippin to have a silly vision. It would even keep viewers in suspense if they, like Pippin, were largely in the dark until the arrival at the city; if you want a visual cue you can point out how close Mordor is (as the film often does) to emphasise why we're now at Minas Tirith.

I feel like the filmmakers often weren't confident in their ability to express the plot cinematically, which is why they invent these "mystical" shorthands.