yuzu doesn't have Vulkan support yet, but apparently it will very soon.
I see no reason to buy an AMD GPU on Windows, unless you literally never think you will use an OpenGL program.
>What about amd CPUs
They're great, but really only Ryzen third-gen which greatly increased single-core performance. Ryzen third-gen is the only CPU makes sense to buy right now. When Intel comes out with their next gen and fixes all the hardware vulnerabilities, then things might change, but as of right now, either buy Ryzen 3 or just wait.