To illustrate the effects of administrative suppression of free speech one can observe that Russian propaganda freely blossoms on the platforms where free speech is significantly administratively suppressed, ie. for example FB, Twitter, LinkedIn - the places where speech violating various "safe space" rules is handled by getting administratively deleted. Russian propaganda is a product of a free speech suppressed environment and easily thrives in such conditions. The rebuttals to Russian propaganda on those platforms gets reported by Russians as harassment and bullying and thus frequently gets deleted, and as a result the Russian propaganda stays there unchallenged or weakly challenged at best. One of the main point of Russian propaganda is rationalization and normalization of the actions of their fascist regime, and such rationalization/normalization naturally fits the "safe space" rules of those platforms, while denying "safe space" to that propaganda is one of the most important thing in fighting it, yet those platforms in many cases de-facto help Russian propaganda by allowing it to highjack the free speech suppression machinery on those platforms.
Compare that to for example HN and Reddit - the places where free speech has much less administrative suppression and where the speech is mostly moderated by the community. There is much less Russian propaganda in those environments because any time it appears it gets strong rebuttals which stay together with the propaganda. As a result anybody exposed to that propaganda here gets also exposed to the rebuttals, and that is naturally net loss to the propaganda, ie. the propaganda can't thrive in the environments where free speech isn't suppressed.