It feels to me like the only logical economic future for game streaming is as a value add for a game subscription service (so like, xgp and xcloud as a logical pairing).
You are not going to compete with high end hardware/graphics using Stadia, not sure if that was solved but for quite some time they just upscaled to the promised resolution instead of actually rendering it.
Everyone casual will be kicked to the next set of consumer hardware by Microsoft(Windows 11 incompatible) or Google (required native codec support for some android apps) either way.
That $100 or so (definitely way more) is going to go on top of the hardware upgrade treadmill, not as alternative to it.
But sorry, it's apparently $200 a year now, not $100. My bad.