Is there a technical reason you don't mention ChromeOS?
Just asking out of curiosity.
Also, the screenshots I've seen of webOS makes me long for a revival... not only on smart TVs
Personally, I dont consider chromeos wheb thinking about operating systems because it's not a real os, its a toy released by a shady advertising company. (Same as android.)
Not the parent, but: ChromeOS isn't what I'd call a web-based OS. It supports Android apps, and that's how you get a lot of things that don't have web versions. Not much different from how Ubuntu can run Chrome and also supports native apps.