TV stations and radio channels are under government control. The government is the one who controls the licenses for spectrum.

it is a place where a very large cohort of the general public go.

Unless your are completely inept at technology and you have no regards for open standards, there is zero reason to think "just go wherever the audiences are" is a sensible strategy for public institutions.

The internet at large is still accessible. RSS is still a thing. Email is still a thing. If people really are so interested in following status updates from the government, they can easily go to the government-owned website. We are not talking about someone running a food truck and wants to reach customers to sell burritos. We are talking about entities that are so large that they make their own gravity.