When doing realtime 3D hardware-accelerated rendering, the GPU is being used and needs to be baseline.
This is notably unlike emulation for the SNES and such, older systems.
Yeah, but the graphics aren't mind blowing or anything.
I'm pretty sure even an iGPU could easily handle the workload.
Systems with a powerful enough CPU generally come with a powerful enough GPU, anyway.
Get past the CPU bottleneck and your pretty much set.