I think I read something like this in a Hacker News comment around a week ago and I've been thinking about it over last few days.
My dream device is something like a Chromebook. A machine that just runs web apps but isn't strictly tied to Google.
I agree with this thinking. I think there's room in the market for this kind of device.
It would still be a computer (file system, terminal) but the operating system would be mostly web based.
All apps would run in a lightweight browser environment like Arc or Safari.
There would be really clear guidelines for how to build apps for the platform. Just use web technologies but have an SDK (a really well documented and maintained SDK) to access lower level components kind of like how Expo does things.
In terms of devices you'd start out with a laptop but then potentially have a phone as well.
The ideal customer for the device is hackers (software engineers) and the education market.