Not the person you responded to, but more tabs visible at once & being able to group them as a tree is incredibly useful.

The grouping as tree thing happens automatically in sidebery (extension for firefox). When you have a tab open, any link you click will be added as a child node to the current tab. If you’re doing research, or just don’t want to lose your focus, it is immensely helpful.

Brave supports vertical tabs but doesn’t do the tree thing. Not useful at all compared to sidebery tbh. I don’t know how Edge works in that regard though.