The whole gendarmerie in France switched more than 2 decades ago first to libreoffice (was openoffice in earlier days) then to their own ubuntu fork.

But it worked well because it is military, they can manage long term projects without too much external interference and there is zero friction (if the head decides, the rest follows without asking).

In regular public administration, decisions can easily be overturned depending on results of each elections and it is not uncommon to face internal sabotage.