Glorified home server to gaming PC

A few years ago I built a glorified home server PC, I'm considering dropping a decent video card into it and trying to use it hooked up to a TV as a Linux running Steam machine-esque system, but I'm not sure if it's worth it based on the other specs. I know the CPU in particular could use an upgrade, but as is should I bother dropping something like an RTX 5070 in it?

https://pcpartpicker.com/list/LnrBDw