While it might not be as much, it still will be something.
I work in a purely windows environment because our main software does not really exist outside of it. The hours of IT troubleshooting for the most inane things I see happening is a pretty penny as well. The newest curiosity is Teams killing my RDP session once it loads in the GUI and the IT team is utterly clueless why. It doesn’t make sense, it doesn’t happen to anyone else and the only way to stop it is to kill the process via taskmanager.
And while a government might not be able to go FOSS, there are tools for communication that aren’t built like Teams.
My SO is in a government job and most of their software is some adaption on SAP or similar. They don’t have any chat apps. They use mails or telephone. They do have Skype, but that thing is a performance nightmare in their environment so they only use it if they absolutely have to.
Same goes for stuff like OneDrive. Even if you could wrangle it enough that it fits data security laws, it isn’t something they use in their daily work.
Define medium size.
All messages notifications? Hell no never, not even on my own less than 10 persons server.
Stuff like announcement role pings? In servers I care or the roles let me filter very finely yes, irrespective of size.
@everyone pings? Only on servers I care a lot about or that use them sparely.