It is becoming harder and harder to install software on systems without internet connectivity. More and more things assume they can hit maven or npm or random other places at deploy time; even expensive well regarded third party software. At least Golang deploys are ok. (Source: running prod systems with a mandate of no internet connectivity).
Major mission critical systems are managed by the country's Ministry of the Interior, and haven't had a major hack (yet), as far as is publicly known.
And besides, how are those poor souls gonna connect to Facebook during their mandatory 10 o'clock coffee pause ?