You could. You would need some sort of dock for HDMI/DP output but you can run just the motherboard by itself, though you would also need cooling. If someone made a fitting heatsink/fan you could make a little case that has a built in USB C hub and turn the motherboard into a mini-PC/console pretty easily.

When I was repairing my broken motherboard after my failed RGB mod I tried powering up the motherboard by itself with a dock and display and it booted up just fine. Would be a good repurposing of that board since the thing that died was related to the built in game controller and that isn’t needed on a console. If Valve or iFixit sold replacement motherboards I’d replace my bodged repaired board with a new one and repurpose the bodged one for a console.