Last time, the hardware was barely capable of driving a 1080p display at a constant frame rate with more than one app open.

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.

I guess I fail to see where people will use this then.

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?

I think the point is that software wasn't ready and now it might be.