One problem I see is that (e.g.) Qualcomm Adreno GPUs don't even run most Windows games well when executed natively under Windows, due to games only being optimized for GeForce and Radeon. I assume this problem only gets worse when trying to run DirectX games through some sort of translation layer with FEX/DXVK.
Sure, you are translating DirectX to Vulkan and that work is done on the CPU. So it may need emulation. But the Vulkan instructions passed to the GPU are effectively native. The amount of work the GPU has to do to execute against those calls is the same regardless of CPU architecture.
