So would it make sense to sell a folding plastic shell with screen, keyboard and trackpad in it that you can bring in your bag and pull out to plug your phone into it?
Where are there going to be setups where they can plug the 3 things into their phone that aren't already a computer that you can just use as-is?
These days, phones are more powerful than the laptops they give to kids to study on.
Samsung DeX has existed for years and works as well as it has for ages. We don't need to wait on Google to make this work. At best, Google will make this type of tech available in software so you can Chromecast/Miracast/whatever it to your display when your cheap phone doesn't do DP-Alt mode.
What I think this is more likely to be about is ChromeOS being killed and Android taking its place. It's not secret that Google is working on that, this just seems to be someone dogfeeding the latest build of the desktop Android build.
But this can also be cast to a tv, for example. I assume you can use the phone itself as a trackpad. So the only extra hardware you need is a cheap Bluetooth keyboard which you can get for $15.
That's 14 years old. Kind of crazy this concept hasn't developed more in the meantime.
If I wanted a weird small portable computer, I would buy a steam deck with a "Decktop" [3]. Or, this awesome modern thing [4].
[1] Mid 2000 Sony model: https://www.ebay.com/itm/388376162735?chn=ps&mkevt=1&mkcid=2...
[2] IBM model with expanding keyboard: https://www.youtube.com/watch?v=lvcl4kmOxPo
[3] Desktop steam deck keyboard stand...thing: https://www.youtube.com/watch?v=HXZuAWYujm4