At the very least I expect to see it used in "IoT" devices like Nest thermostats and stuff like that. Whether it ever replaces ChromeOS or Android is impossible to determine at this point though. Almost every attempt at running Android apps on another platform for compatibility has been a failure. Microsoft seems to have given up on it entirely.

Wouldn't that be where Flutter could come in handy? If the same codebase cross compiles to Android and Fuchsia (hell, even iOS), lack of apps won't be an issue.

The Android team doesn't seem fond of Dart/ Flutter, but that's not surprising. Who wants to voluntarily sign their death certificate, so to speak?

I could be wrong, but I imagine at least some people in the Android team would like a fresh start.

I don't know. Fuchsia seems like a sufficiently massive effort to at least have some goal other than experimentation.