What you experienced (degraded graphics without lag) is not cloud gaming per se, but Game Pass cloud gaming. In fact, the first couple years of Game Pass cloud gaming the graphics degredation and severe clumpy pixelation was such that it *usually* was not playable. Now, it is much better, but still usually noticeable.
Geforcenow and Stadia (now discontinued) never had that problem. You can now stream Starfield within Geforcenow using your GamePass account, and it works much better, essentially like playing local if you meet the recommended network specs.
I don't know why GamePass struggles with this so many years after it was perfected by other companies. Maybe it has to do with Gamepass streaming from Xboxes, rather than PCs as Geforcenow does. Or maybe it is related to heavier network congestion with GamePass. But other than incessant sign-in screens, I've rarely had any ussue with Geforcenow (I've only tried 1080p), and I never had a problem with single player Stadia.