Cant a argue with that ..although I bet with RT and improvements to AO and RT, they wouldn't have been able to achieve 1440p/60While I admire them for sacrificing resolution in favor of fidelity (something Insomniac and Bluepoint shouldve done instead of targeting native 4k 30 fps), I dont agree with your overall thesis.
AC Unity was a 900p game running at sub 30 fps so its pixel budget was roughly around the 1080p cb Horizon FW is putting out. Doesn't really mean it has any effect on the PS5 tbh. I mean the PS5 is still native 4k 30 fps. It is wasting a lot of precious GPU power rendering pixels instead of introducing new visual features that make it stand out even more. What they have done is basically the equivalent of low vs high PC settings we have had since well, forever in the PC world. The game still has LOD pop-in issues when traversing on foot, let alone when flying. Fog is everywhere even on the PS5 version. Instead of wasting half the GPU rendering pixels, they shouldve focused on better LOD management by utilizing the PS5 IO and more visibility and reduced fog among other things like ray traced reflections or at least ray traced Ambient Occlusion and Shadows which makes a massive difference to foliage quality as seen in Dying Light 2.
What they have done here with the PS5 version is good, but not exceptional. Hopefully, their next game will also target 1440p or 4kcb and push visual fidelity instead of pixels like they do for the base PS4 version.