We should be fair, remote gaming and game streaming service isn’t an evolutionary idea, a lot of competitors tried it in the past. Still looks new, this is because they all failed to succeed.
Anyway business gave another shot, we have currently a lot of initiative in this field:
What is the basic problem Google and other competitors needs to face?
You use only a remote controller and an installed app on your selected screen device.
It is true that from hardware point of view most of your current device is strong enough to stream in full HD (4k streaming still could be problematic for a lot of TVs, phones, tablets). It requires only a hyper-optimized streaming application.
Game streaming isn’t a Netflix
The problem is that 80% of US households does not have the sufficient internet connection to use such a service. You could say it’s bullshit, Netflix works everywhere. Don’t forget Netflix isn’t a live service, it buffers the movie as much as it can, to play flawlessly to you.
When you push the “forward” key on your controller it takes 20ms to the hardware device (server) to receive the command (which runs actually the game) and you will receive the feedback in another 20ms to your screen. Basically this kind of service doubles (or at least extends) your ping time.
I think a bigger problem is the stability of the network:
You probably have an in-house wifi network (old wifi networks could be problematic)
You may have a not 100% stable net provider (remember stability means constantly low response time)
You may live in an area (country, region) where your net provider may not have direct connection to the Google Stadia’s servers (which could result unreasonable lags at the end)
All of the above point could result a terrible gameplay experience, even when the Google Stadia’s servers are so strong they could deliver 4k gameplay experience at 144hz.
My personal experience
I do use my Xbox in-house streaming service, where the stability of the network only depends on my wifi network. I used a fairly old (not including 5GHz technology) TP-link wifi router to cast Minecraft to my laptop (fast solution for children request). I even paid attention to sit not so far from the router.
End result: it was playable, but a terrible experience. It disconnected only 2 times during a 2 hours gameplay session, but the quality of the stream jumped up and down (between 1080p and 480p) constantly.
So far I switched to Linksys Velop mesh wifi and I made the same test again.
End result: it was slightly better, but still bad experience. It doesn’t disconnected from the streaming session, but the stream quality still jumped between 1080p and 480p.
Ok, now imagine how would be the end user experience if my internet provider would come in to the picture with a Google Server located in 4,000 km distance (default 30 ms ping time in addition).
I would say live connection and streaming is the future, but internet providers are still behind. Stability was always an issue and 4G doesn’t solve anything (in terms of ping time).
Note: I live in Hungary which country offers the 9th fastest internet worldwide, in comparison US is on the 20th place on this list.