By comparison, shipping "edge devices" (aka, uh, COMPUTERS) running an 845 Snapdragon or Tegra (like the Switch) is cheap and getting cheaper. What makes more sense: asking someone in a developing country to pay $200 one time for a general purpose computer useful for everything including 1080p gaming, or $10/month in addition to, uh guess what, some computing device they'd already have to own to access Stadia.
The adage goes: never underestimate the bandwidth of a station wagon full of tapes barrelling down the highway. I mean, the follow up is usually "but never forget the latency", though in this case that doesn't apply. Point being: the internet isn't the answer to everything, but if the only tool Google has ever known is a hammer then every problem is going to look like a nail.
Also, to point 7. guess what billions of people can't afford a console or an expensive PC rig. Yet, in developing countries data is already very cheap if not free. So, this DEFINITELY is a big step closer to unlocking games for them.