Only 74%?
That feels wrong.
I don’t know a single company off the top of my head that wouldn’t suffer serious damage if you null-routed Google and Microsoft’s servers.
Excel rules the world, and even if it didn’t: nobody is running libreoffice on linux professionally, at least not that I am aware of- and hosting mail? Conventional wisdom is that you should outsource that: I don’t seriously believe that people would outsource mail and not go with Google/Microsoft and get a productivity suite “for free”.