One thing I noticed in my short time playing God of War and then sitting and watching while my friend played it. They use a LOT of fog. And the areas without a lot of fog feature relatively simple world geometry (sea/lake) or basically are broken down into a bunch of interconnected mini-areas.
This allows them to really concentrate resources on the visible areas. For example that shot with the Turtle above the house in the glade in God of War features a very limited and simplistic scene. But that allows them to put a lot of resources into what little is actually in the scene.
That's a lot different from say an open world game with a large view distance and unrestricted views. Right now I'm watching my friend go through the 3rd area (the one after the lake/sea) and it looks great, but there's also a whole crap ton of fog hiding anything beyond a very short distance. Again, smart use of fog to allow increased detail closer to the character.
When there isn't fog, the play area has either very limited view of anything beyond a short distance (caves, fighting arenas, canyons, etc.) or an expanse of simple scenes (the sea/lake area). So far, it's been extremely rare to see a large expanse filled with lots of things (like Far Cry 5, for example).
Going through the current God of War reminds me a lot of the PS1/PS2 era where fog was used massively in games to limit viewing distance. Same thing is happening here, just with much much greater fidelity close to the character.
Perhaps things will open up later and show something really revolutionary, but at the moment I wouldn't say it is necessarily better than other games.
However, it does look really good. That said, I found HZD far more impressive due to not having to use heavy fog or a ton of interconnected mini-arenas. I do wonder if part of the reasons to choose Norse mythology in this game was due to the environments where heavy use of fog and mountains to limit scene complexity (with regard to rendering distance) is logical considering the locations.
Graphically speaking God of War is not so much open world as much as a linear corridor type of game. Gameplay wise, it's sort of open world with Metroid style revisiting of old locations.
Before people think I'm putting down GOWs graphics, I'm not. I find them very impressive and it's interesting to look at all the ways they used to accomplish it, including things they used to reduce how much needs to be rendered in order to put more into other areas.
Regards,
SB