Recall:
Available bandwidth is likely the largest factor here.
Consoles need to compete with CPU bandwidth and PC's don't, so making cross comparisons to PC benchmarks may not always work if you're looking strictly at clockspeeds/TF. Except in scenarios where bandwidth is not the bottleneck.
If you have a CPU that say normally takes 10GB/s at 30fps (heavier CPU titles will eat more, more NPCs = more CPU action), it becomes 40GB/s at 120fps. That combined with the disproportional way that the more bandwidth CPU eats up, there is even less for GPU as per the older PS4 slide, the GPU is starved for bandwidth.
This is likely the main culprit for resolution loss before you look at clock speeds, fill rates etc.
So 448GB/s becomes 408GB/s off straight subtraction, then take even more off even more for disproportion and you have a GPU that is unlikely able to hold higher resolutions at higher frame rates. You're going to be well sub 380GB/s.
Then you couple that with higher CPU usage pulling back any sort of smart shift towards the GPU, and you're in a scenario where PS5 cannot produce superior results compared to something like 5700XT.
5700XT will have all 448GB/s to itself. CPU completely unaffected.
These are typical challenges for game developers working with consoles, and not every developer is capable of maximizing the hardware for every games the same ways as some of our best AAA teams can.
4K60 and 1440P@120 are hard targets for consoles to hit (due to the sharing with CPU factor) and will increase in difficulty as the generation goes on. Aside from memory footprint concerns, which SSDs mitigate, there has not been much added hardware to mitigate the bandwidth bottleneck. The more computation you are doing, aka, saturating the CUs, ultimately means you're pulling more bandwidth as you've got to write the results somewhere. The bandwidth will likely be the ceiling here for both. they will need to come up with creative ways to reduce the bandwidth pressure, and that likely means some creative up-sampling techniques.