I think writing is inherently scary because its more or less permanent. Thoughts are fleeting and lossy, but there’s comfort in this lack of state. Its easy to confide in your strokes of genius or dismiss stupidity when such musings pass as quickly as they come.
Distilling a set of complex thoughts into a sentence or paragraph forever exposes the idea to the lens of public scrutiny. Now its captured and somewhat eternal. I think this cultivates accountability. The public forum is a wonderful motivator for due diligence and integrity of thought.
If said forum is the internet, there is no shortage of scathing tongues and opposing viewpoints. This is a blessing. Feedback is instant, and writing becomes a living process that helps you find true North. The name of the game here is how fast you can find out you are wrong. Being right is fun, but it never helps you grow.
To expose your ideas to the limelight of the truth is to see just how strong the rational bedrock of your thoughts really are. The weak ones tend not to survive.