This is exactly my take. It basically holds for Signal too.

The question of self-censorship is too often overlooked IMO. The knowledge that nobody is reading your messages except their intended recipients is empowering and liberating. No one is filling a database with information about you and your friends, because they can’t. You can say exactly what you would say at the dinner table and not think twice about it.

In a police state with mass surveillance (we all know the big examples) you don’t have this privilege. Whether or not you think about it consciously, you are constantly monitoring and policing what you say - and therefore ultimately, to some extent, what you think.

I’ve been in a couple of those places recently. I can tell you that just the banal act of using Signal there (sometimes over VPN) felt almost exhilarating, like jumping the prison walls.

In historical terms, free speech is a vanishing rare thing. It absolutely is not the norm and it bothers me that so many people in the West don’t seem to know this. We should not take it for granted.