True, but if you remember the books weren't exactly the most detailed things ever. The movies did a lot of fleshing out for the characters and laid down more concrete lore, which was left fairly vague in the books and much was left to the imagination, which does result in inconsistent lore since much is based on individual interpretation. Tolkien was very good at weaving a good story, but the characters were a bit shallow from what I remember. It's been a good while since I actually read the books, though, so I may be remembering things incorrectly. But let's not argue lore, if Ancalagon's out Sauron's the next viable option, who we all know for certain to be a real threat. Most of what we do is up to you guys, I was merely bringing up options and stating my opinion on what's been stated.

And the reason we're still in Hyrule is because we're not actually trying to finish the game's plotline, we're searching Hyrule for the crucible piece, which isn't necessarily gained from finishing the plotline.