GeForce Now is working great for me. But for this person's dad, it probably wouldn't work well at all. The interface is cluttered with game icons. Which is fine for me. But someone averse to tech would probably find it confusing & overwhelming.
Be warned though, Red Dead Redemption is not available on Geforce Now. Maybe someday... they just started integrating Microsoft Game Pass games onto GFN, so maybe RDR is on the backlog there somewhere.