Office already runs on Chromebooks via Google Play within the Android container [0]. Is it then worth MS' time and energy to port the browser interface as a Chrome OS 'native' app?

[0] https://support.office.com/en-us/article/how-to-install-and-...

o365's web interface is pretty much what you're asking for. It's a rent based model, but so are the desktop apps at this point (mostly). It wouldn't really surprise me to see an electron wrapper around o365 UI for a future release to unify the applications more.

The only part of "Office" I really even use though is Outlook (at work), and it's pretty good at the job it does.