Yes, it is an extremely dangerous power. It is also, unfortunately, sometimes necessary, especially in emergencies. I'm generally strongly opposed to eminent domain when it's used for "economic development" and other such goals, but COVID was a textbook example where it was warranted.
And as for the difference between "speech" and "action", what the released emails show is that the government didn't stop at speech - it used Twitter as a proxy for censorship, and censorship is an action.
It is the difference between action and speech. Action is generally more dangerous. It is a little weird to me that in this discussion of the dangers of the government limiting speech, some people are more fearful of the government's speech than the government's action. It is a lot easier to simply ignore what the government says than try to hold on to my property when the men with guns come knocking at my door.