As someone who manages socials for corpos I have to completely disagree with you. Some platforms absolutely force you to use the app either by making you finish setting up your account in one, or by making their web app so broken/annoying you have to use the app for your own sanity. Also, like others have mentioned, you want to see what your users are seeing.

I am one of two people in my company that has access to our social media accounts. The other person is in marketing and uses the platforms for ad management. Our company pays for our personal cell phones because of this.

We also want to be on every platform, and we always want to test out new platforms, because we want as many people to see our messaging as possible. The same goes for whatever the state is trying to communicate.

This all being said, the state can absolutely provide secure phones that allow socials to the folks who might need to be able to access them. And only allow it for those specific folks. They can also provide them a second phone for all other work related needs.