I don't know if it is. Most businesses seem to use the web-based Office365 interface now, rather than native Office.
I expect the biggest reasons businesses use Windows these days are momentum, and lower support costs (Linux is still less reliably than Windows on real laptop hardware).
I work in an area where large heavy collaborative Word documents are very commonplace.
I've tried very much to make this work on Linux with the web apps, but they're just not good enough - not feature complete, and quite slow and clunky compared to the native equivalent.
