When you speak, you get instant responses from your audience. You can see their reactions, hear their questions, and adjust your thoughts accordingly. This dynamic interaction allows for clarification, elaboration, and even a change of direction in your thought process.
Writing, however, is a more solitary experience. You are writing for an audience that is not present. You don't get the immediate feedback that helps you refine your ideas and ensure clarity. You have to anticipate your audience's reactions and questions, which can be challenging and lead to potential misunderstandings.
This lack of interaction can also make it difficult to maintain momentum and keep your thoughts flowing smoothly. In conversation, the back-and-forth naturally helps to keep things moving. When writing, you have to find ways to sustain your own energy and avoid getting stuck or losing your train of thought.