The more important (and interesting) question that should be asked is - what caused, (or why did?), the developer to make a conscious choice to target a lower resolution and shadow quality in this particular game?
Up until now - all cross-gen games for XSX and PS5 have been (generally) equal in output (assuming latest updates/patches in play... ).
Per the article - the FPS drops are rare and inconsequential:
"Put simply, it's 60 frames per second... with just one exception in our hours of play. In the Mendoza mission set in Argentina, it is possible to see Xbox consoles run between 50 to 60fps around a field towards the outskirts of the level, while PlayStation 5 remains constant at 60fps. Hopefully IO will look at improving this for owners of the Microsoft machines, but everything else we played ran flawlessly - bar a very slight stutter in a cutscene at the beginning of the Miami stage from Hitman 2, where all consoles dip from to near 40fps. At this point though, it feels more like a nitpick rather than anything that would have an impact on any specific purchasing recommendation."
The biggest difference is resolution and shadow quality:
"Meanwhile, there are additional tweaks to shadow quality too. Series S uses the equivalent to PC's low quality shadows (in common with the last-gen base console renditions of Hitman 3), while PlayStation 5 runs at medium (similar to One X and PS4 Pro) and Xbox Series X operates at high. The difference is fairly subtle across all three, but it's there nonetheless. In all other scenarios, all three next-gen consoles are the same and the overall presentation is first class. Yes, Series X's resolution advantage is there, and the Glacier engine thrives on precision, giving it a pristine edge. With that said, however, the lower resolution on PlayStation 5 is in no way a problem and still looks wonderful."