Why I had to stop using vertical tabs
The author explains why they stopped using vertical tabs in their browser, citing issues such as reduced horizontal screen space for content, incompatibility with some websites and extensions, and the discovery that traditional horizontal tabs were more efficient for their workflow after using vertical tabs for an extended period.
Background
Vertical tabs are a browser feature where tabs are displayed in a vertical sidebar instead of the traditional horizontal row across the top. They've become popular because screen resolutions are wider than they are tall, making vertical space more valuable—and because tabs get compressed into unreadable stubs horizontally once you open more than a handful. Arc Browser and the Tree Style Tab extension for Firefox made vertical tabs mainstream, and Microsoft Edge and Brave have since added native support. However, some apps and websites don't render properly when the browser's sidebar reduces the viewport width, causing layout breakage, clipping, and horizontal scrollbars—the problem the author hit which forced them to turn the feature off.