What the reason for 6 FPS in "that Atlus game" with ~60% CPU & ~34% GPU utilization?

My GPU is 9 years old. It's a lot worse than yours, it doesn't even support Vulkan. The problem that it never gets loaded for 100%. Even 50% load is rare at emulation. So... it should not be bottleneck. Same as CPU never reach 100% load. Something weird happens. I would understand if my GPU were loaded for 100% - that means it can't give more FPS, but it's not, same as CPU.

And... that's just a mystery.
P.S. I do not name this game to not cause devs any problems. So if Atlus decide to find more copyright-protected junk on emu's site it will find nothing.

If it's 9 years old, it runs pixel shader 4.0 and RPCS3 needs pixel shader 5.0. That would explain the low fps.