Perhaps the most valuable behaviour to manifest from free speech is the escalation of ideas to power.
If we visualise a group of counties that have authoritarian hierarchical governance where free speech is suppressed, those in power have very tight avenues for where they can receive new ways of thinking.
Usually restricted to established associates within official organisations, these pathways to power represent a fraction of the people who are governed. The conversations in those organisations will be tightly controlled, so to conform to a preferred ideological view.
Such a stifling of development serves to preserve those who are in power and their ideological beliefs. A setup such as this imposes on the many the inclinations of a few. The mood of a state is a reflection of the temperaments of those in power. Huge power differentials are created between those with and those without official status, while status is controlled by those in power – including the status of ideas.
If we visualise a group of countries that have primary governance of free speech, a miraculously different culture emerges. Instead of a tiny amount of people in a few stifled corridors to power, the entire population becomes the bedrock of ideas within those countries. An idea can originate in any area of the population by any individual, gain respect from those who come into contact with the new idea, and ascend through the population on the merits of its wisdom. Before long, better ways of approaching a matter will naturally reach the corridors of power. Evolution of ideas through natural appreciation is exponentially more effective and prolific.
The entire population act as a resource for how best to define a problem and approach a subject. In this manner, advances in civilisation are optimised most rapidly by ascending the best ideas into power.
Thus free speech is a primary driver for a flourishing culture.
Free speech manifests scientific theories as opposed to ideological beliefs.
Therefore believers in ideologies and those who want to impose their inclinations on the masses are those who oppose free speech.
Fully flowing ideas represents the escalation of the best through perceived merit.
Free speech and transparency are an infinite duo, for sunlight is the best disinfectant.
Transparency allows an entire population to perceive the issues at hand.
The best responses of a culture are then brought to power by free speech.