I totally get how games have a million things to deal with at launch, how maybe it can't get optimized in time, the platform changes, etc, etc. No issues.
What I am totally baffled by is how Google seems to be completely indifferent to how their system is perceived by gaming enthusiasts. If they wanted, they could pay Bethesda/ID $10m and say "make Stadia the BEST place to play Doom eternal at launch, barring high end PCs". It really feels like they just don't care at all, and other stories echo these sentiments - that Google offers very little incentive to devs to port, and almost none to optimize for Stadia.
Its like they own a gaming environment but view it just as a place to experiment rather than as a business to grow and be proud of.