You really don't. I have a dell optiplex micro in my livingroom with an i7 and 16gb ram running kde plasma and a couple of 8bitdo controllers. I can play anything an OG gamer would want to play on that. It'll even run castlevania for the PS3, and with Intel gfx.

Plus it has a full desktop and kde connect, so I can do anything else I want on it too, e.g. kodi, and run everything from my phone. I rarely even have to touch a keyboard or mouse.