None of these tech companies have shown they have any idea what they're doing with video games.
Gamepass got in the door first like Netflix did with video streaming and have already built up a strong install base and library so there's no way this is some potential Gamepass killer.
Google is hilarious. They rolled out Stadia as a rival to next-gen consoles, but once MS did the Bethesda deal they said "We just gonna be a side dish, not the whole entré" and closed their internal studios before they ever made any games
People think Stadia actually is actually dead when all they did was back out of developing exclusives, which goes to show how terrible they've been with their messaging this entire time
Honestly I expect Amazon to be the bigger competitor once Luna gets out of the closed beta stage simply because I expect them to be more aggressive than Google on all fronts, and their initial marketing rollout did a much better job positioning itself than Google did with Stadia.