By default, Zulip limits the width of the center message pane, because it's easier and faster to read paragraphs that don't have long lines. This is also why many news sites, blogs, and social media platforms limit their paragraph width.
You can instead configure Zulip to use the full width of wide screens.
{start_tabs}
{settings_tab|preferences}
- Under Information, select Use full width on wide screens.
{end_tabs}