Some scenes would pass as documentary footage. That's how good CGI has become.
It made me think of simulation theory, how if we live in a simulation, what we see can be picture perfect realism because the technology is getting there. This was perfection in some scenes.
So... if they look so great, why they're not used more often in CGI?
If you use photorealistic CGI landscapes, then you must use photorealistic CGI characters. And here comes the problem: those characters doesn't fit well. They look stiff, fake. Check the Hobbit, check Polar Express. When you rewatch the movie, this feeling becomes even stronger. Think about the Hobbit. Right now, one the first things that comes to the mind is how fake the orcs looked when you compare them with the ones in Lord of Rings.
That's why almost every CGI animated movie doesn't go photorealistic. For living characters, it's not there yet. And if you go lowpoly with the characters, then you must do the same with the landscapes. The best CGI ever must be a whole pack. It doesn't work when having stunning photorealistic landscapes forces you to have non-expressive characters.
I'm talking about the landscapes, anyway. Yes, the landscape is mostly real, except when they plonk down Minas Tirith, Helm's Deep or even Bree in a random shot. They still looked good, though.
Yeap. I think Peter Jackson became the new George Lucas there. They're both genius, but they really need people around that can draw a line in the floor and say 'no' to them. LotR vs The Hobbit is very much the same story than Star Wars vs prequel trilogy.