Most people warning about the danger of echo chambers don't actively seek out anyone truly different from them.
Censorship is rocket fuel for conspiracy theories.
Legacy social media content policies assume you are completely incapable of thinking for yourself. As if we all become helplessly brainwashed by everything we see. It shows a total lack of respect to user intelligence and capacity for education.
Defending free speech is like brushing your teeth. It's just something you must do to be healthy. You do it even when you don't want to, and when you don't, the system starts to rot.