> the French Gendarmerie for instance now uses a Linux-based LibreOffice-based workflow for all its internal IT.
Not for all internal IT. They use Linux as a web browsing kiosk and for very basic document editing and email. Which it is capable of coping with for front line police who's main use of IT is filling in forms. They still commonly use Windows in areas that require business applications - e.g. back office and finance. The migration is "completed" and they still run Windows on ~ 12,000 desktops.