Emptiness of the oppressed
Freedom of expression is a basic human right. Without it you are forced to talk about things that don’t matter. Things that are empty of substance. Nobody has the right to take free speech away from you. When open debates are not allowed, the society is ruled by tyrants with guns who can do anything they want and stay in power as long as they like.
Your eyes see and read things, and your brain processes them. If you aren’t free to discuss those thoughts, because you would be put into jail, soon the brain will subconsciously shy away from being skeptical and you just follow obediently what the dictators tell you to do. Being good is equated to being a good follower who doesn’t question things. Then critical thinking capacity is diminished from the society, leaving it void of substance.