So far we haven’t seen any enhancements in terms of graphical fidelity on PS4 Pro. PS4 Pro versions of the games just offer high resolution and even Horizon Zero Dawn which happens to be one of the best looking game on PS4 Pro and PS4 as well.
The game was officially confirmed by developer that it’s using the same graphical assets as regular PS4, the fact that it just look better is because it’s using custom version of checkerboard rendering that brings out more details.
If developers tries harder, optimize and customize it properly they will be able to deliver good looking games. However, that’s not always the case because, not every developer cares to deliver. Sometimes those games do not comes with higher textures i.e: exclusives. And PS4 Pro version of those exclusives do not bring too much to the table apart from high resolutions.
Although in most cases they are not even offering a better performance. For instance Horizon Zero Dawn, A regular PS4 runs it at stable 30 FPS just like PS4 Pro. Graphically it cannot do much, all it can do is just run games in high resolution because there’s not enough memory on PS4 Pro to add extra graphical effects.
But if we talk about performance then, 60 FPS makes the difference which is a good thing to have on PS4 Pro. However, PS5 is a real game changer in these two scenarios.