Connecting and deconnecting cables can cause damage. It's best to have a dedicated hardware.

Plus, you can literally turn your mini PC into an emulation box to play retrogames (snes, megadrive, ps1) and the new generation of "retrogames" (ps2, ps3, wii, nds). And if the hardware is good enough (modern amd APUs and 16gb ddr4) you can even play switch games on it.