> The counterargument would be that they've deployed a ton of network capacity and GPU resources for cloud computing anyway, and so Stadia is just riding on those coattails... But it's certainly not a promising track record.

Exactly, in fact, Stadia is really just a way for Google to subsidize their cloud GPU buildout. Do you think those expensive GPUs are sitting idle in the meantime? No way! They're crunching numbers or spot instances for AI/ML workloads.