> After a while, I think dust would inevitably get in the hinges and wouldn't fold flat. I've seen demos in stores of newer gen Samsung foldable phones and it looks like those wouldn't fold flat

For your first point, the iPhone duo is rated IP 68 Dust and Water protection. Literally none of Samsung's book foldables so far have achieved this IP rating.

The Pixel Fold 10 (and 11) is IP68 rated