The Rontos never made sense on a desert planet. Such a large creature probably eats and drinks more than they’re worth as a pack animal. And I can’t see them doing heavy lifting like Asian elephants, because they have droids and tech for such things.
True. But at least it’s a reptile, which makes a lot more sense than having a huge furry mammal in the desert;
(EDIT: I’m surprised to see that there’s no canon explanation for this. Not even in Legends. Wookieepedia simply states that they’re “one of the most adaptable herbivorous creatures in the galaxy.”)