Therein lies the dilemma 343 has. It's very unique compared to what Rare and Insomniac have to deal with. Halo is a game that, if they're trying to stick close to the original Halo CE aesthetic and be true to their vision of a spiritual reboot, which means moving away from their more complex, non-legacy designs of Halo 4 and Halo 5, there's no simple way to do that because Halo can't go as full cartoon as Rare and Insomniac does. Personally, I think that shit would look badass if they tried it, particularly if they went full blown comic book with Halo, but I fear the Halo community/fanbase isn't ready for that just yet, and it would negatively impact the franchise and the game's release even if they successfully pulled it off because there would always be that part of the gaming community who felt it looks too cartoony, hence can't be taken serious.
So Halo has this amazing balancing act of both trying to come off realistic, while at the same time ignoring traditional rules of photo-realism and going for something that fits their artistic vision and their world. The cutscenes are going big with stuff like this.
The level of detail is badass, the look is incredible. It's impressive, but not exactly "photo-real" if that makes sense. I've always felt Halo Infinite had a stylized look that almost came off to me as cel shaded without actually being cell shaded or whatever way it could be described. It just always struck me as more "gamey" in appearance. It's going for its own unique version of realism, but at the same time is going for pretty damn convincing human like characters with a heavy military/war tone. This automatically puts Halo in a box different from anything Insomniac or Rare do. Halo has unrealistic/sci-fi weapons and effects, but they can't exactly go sunset overdrive or ratchet with those weapons in terms of the effects. They can't be "realistic" versions of themselves, they also need to remind people of classic Halo at the same time in all things, so that automatically also means recognizable visual elements. Hell, they even gave us the original Halo CE shield regen noise.
But then for gameplay, they need to be this. It's not photo-realistic, it's not using the level of post processing other games use to hide more clean looks at their textures and other visual elements. Halo Infinite is very much giving us a straight look without all that extra post process work.
So not photo real, ESPECIALLY looking at in-game enemy characters, but this game looks damn good. If Halo 4 and 5 were trying to be Batman Begins and Dark Knight in terms of a particular vision, Halo Infinite is back to trying to be Tim Burton's Batman with the first Keaton movie and then again with Batman Returns.
Picture overload, but it helps send the message better I think.
Edit: Recommendation is don't double zoom these pictures unless of course you want to see a whole ton of extra visual annoyances you generally will never see as clearly when just playing the game. A single click is a better representation of what to expect I think.