We tend to use the channels in two different ways. Some channels are for chat; a stream of short messages. Other channels have more in-depth messages (like explanations, articles, meeting notes, etc.). In those latter channels, to communication focuses less on a single stream, and more on the replies.

Currently Mattermost solely focuses on chat streams (chat mode), having replies as an option (literally on the side).

I want to suggest an extra mode: topic mode. It differs from the chat mode in the sense that:
- The main might only show the topics (first level messages), not the replies.
- The reply sidebar should be more wider, making it possible to focus better on the replies.
- The input fields for topics might be larger by default, since it will be used for larger texts.