I've tried to find a flaw with this argument and admittedly it's pretty hard. As long as you accept to pay a above the market price for the game and you don't care about retaining ownership then it somehow makes sense.
I'm guessing this value proposition is what made it unsustainable for Google.
The need for GPUs during an unprecedented spike in demand for chip fab capacity couldn't have helped.
I think the basic model will eventually work out, though. The bandwidth is there. The compute has to be cheap enough that the biz model works by just taking the retailer's cut of the title sale + maybe a tad more. The tad more can come from one-time hardware sales and maybe better negotiated cuts of the sale from the studios. I would never ever have purchased a copy of any AAA title without Stadia and similar services. I think the same is true for almost all Stadia purchases.
But Google's failure here makes sense. It's a low margin game. google sucks at low margin games.
I'm guessing this value proposition is what made it unsustainable for Google.