FWIW, I signed up for both GeForce Now and Stadia, and find Stadia to be both easier to use and better-looking. For comparison, I ran Cyberpunk side-by-side and killed the GeForce Now version after a few minutes.
You bought the game on both stadia and steam/gog/epic?
Yes, for science. It was ~$100 to check if I can avoid spending $2k+ on a PC rig because I can do my casual gaming on a MacBook Air. Turns out I can, so it was money well spent.
If you're only testing compatibility/performance, and so don't play for long, you can request a refund from Steam.