This Seeking Tech article compare the PS4 versions of the original Resident Evil 5 and Resident Evil 6 on the PlayStation 5 Pro.
You can find the video comparisons below:
With the “Enhance Image Quality for PS4 Games” setting set to enabled, both games provide a slightly sharper image. The difference is more pronounced in Resident Evil 6 than in Resident Evil 5.
The PS4 versions of these titles top out at 1080p, even on the PS5 Pro.