As a consumer, having certified static hardware configuration means you know exactly how it’s going to run off reviews on the same hardware. You know that you are going to get support the manufacturer and aren’t going to have to worry about the manufacturer of the motherboard pointing fingers at the manufacturer of the GPU or RAM or CPU if you have a problem. Updates and driver support is all handled by the OS.
But probably the biggest reason is that consoles already have the best name recognition, higher user adoption, and hardware is sold at a discount compared to comparable PCs.