I would say two things. 1) security inherintly is annoying, the more secure something is the more it sucks to use. Military communication channels have to withs

I would say two things. 1) security inherintly is annoying, the more secure something is the more it sucks to use. Military communication channels have to withstand the most powerful attacks in the world, everyone, Russians Chinese Europeans Israelis, would all love to get access. So these have to be extremely secure and thus annoying to use channels. 2) their are laws about storing government communications which are built in to the official channels. Trumpists are suspiciously intentionally breaking these laws.