Outside of Windows and MacOS, there is no OS ecosystem that works as well and at scale for an enterprise level deployment.
I don't get the whole "US" aspect, why bring politics into this? We need alternatives and competition regardless of all that. I don't care if Europe, China or India make it, a viable alternative would be a game changer.
For Europe, they're solving the wrong problem. Solve the problem of low pay for developers, and a stifling regulatory atmosphere that inhibits disruptive startups.
If there is a good and viable alternative, why is it just for Europe? It could boost Europe's economy by selling to America and the rest of the world. The tech needs to be good, if the US can do it, why can't Europe?
Replacing office or one app at at time only addresses surface level issues.