The main problem is that PS5(and Xbox) has unified memory, that's the whole advantage of these systems. You can put your texture in one place in memory, have the CPU write to it and the GPU can immediately read it from the same address once you are finished. It's an absolutely huge performance advantage, that the typical PC architecture doesn't support and doing such a thing will always incur the penalty of having to transfer the data from system ram to GPU vram - with enough bandwidth and fast memory the issue can be somewhat mitigated, but it doesn't change the fact that on PS5 your GPU can start reading the data the CPU just wrote nanoseconds after it's done, on a PC you need to wait for the transfer first.