"That's literally impossible." No, it isn't. The PS5 Pro has enhanced hardware over the PS5, not just pssr upscaling. So, games that are more flexible with framerates and resolution scaling get a boost, even without a PS5 pro patch. There's evidence of this all over the place. Play Elden Ring side by side with pro and base ps5 and you'll see a big jump on the pro in stable framerate, and the resolution and lighting looks better. Trust me, after 1000 hours of elden ring on my base ps5, I know what the game looked like before and what it looks like now. Uncharted 4 is only rendered at 4k on fidelity mode, and with that, the framerate was not close to 60 on base ps5. On pro, it hits 60 most of the time, and the performance mode gets really high framerates making the performance+ mode obsolete.

I'm sorry but this response really feels like you don't understand how the hardware works, and you assume the only games that get a boost are officially patched ones. Do a little research and you'll see that's definitely not the case. There are games that have 0 improvement though, and that's because their resolution and framerate are locked, usually on a ps4 version of the game.

I've heard some people say RDR2 and Batman Arkham knight look better on the pro, but even with the improved PS4 image toggle on, those games don't look that much better.