Don't be silly.
HFW and Ragnarok, even the PS4 versions, look practically a generation ahead of Second Son. I'm not going to bother breaking down exactly why. Anyone can see the difference if they care to look.
Gotta strongly disagree here, just compare same generation tekken 1 vs tekken 2 vs tekken 3, which were on same playstation 1(and footage from there, not cherrypicked screenies).
From that u can clearly see that software had big room for improvement on same hardware (ps1, once again, no arcade/pc emulation, but actual ps1 footage for fair comparision).
Now Comparing HFW and Ragnarok, even to 1,8tf mashines infamous second son, there is clear difference but only if u compare ps4 ISS vs ps5's verion of new GoW or Horizon.
Infamous Second Son was open world and looked pretty amazing early 2014 already here tons of footage from launch, DF aproved framerate test, so u know game was solid/always above 30fps, not some 15-20fps dips fest
I played ps4 version at launch and it was magnificent, game quality was solid and graphics/gameplay wise u fellt right away its next gen showcase( back then, early 2014 ;P)
I would say the feeling was comparable to playing demon's souls remaster for ppl who didnt play og game on ps3(very few actually played it, big props to sony for remaster)
especially its 1440p60fps mode.
I think in terms of sony's first party output/performance/quality (first party so not counting forspoken ofc, which looked worse from even many multiplats, hell it looked worse from ff15 on ps4 which is running on same engine even ) software isnt the bottleneck like it was in early ps1 days(hence huge improvement in later years of first playstation), but bottleneck lies mostly on the hardware, aka we need stronger mashine, so ps5pro will be perfect solution for that.
Once again- expecting games looking like in fidelity/resolution mode, but running/performing like in performance mode, maybe with bit of rt on top (since by then rdna4 will be much more accustomed to rt, not only stronger gpu but simply rt effects wont have as huge impact performance wise like they do on base ps5, aka rdna2 architecture ).