Free speech regimes fail and are replaced by those that censor, because censoring exercises power, whereas free speech exercises none. Thus people attracted to power will find some way to censor, and then to increase censorship.
The exception is when free speech is being used as a wedge to destroy the old regime, in which case free speech exercises power, because it is being used to commit lese majeste and revolution.
Truth wins in the long run, when everyone is dead. Power wins in the short run, while the relevant actors are still alive. That's why it's called power.
On the libertarian left-hand side of the scales of state, one has the virtuous population's dedication to truth. On the authoritarian right-hand side of the scales, one has the ambitious population's attraction to power. Add leaden lies to the left-hand side until the two balance, and one discovers how much the regime rejects reality.
You change it to a nerdy adjective.