I used them back in my student days but then I realized I needed to stop opening so many tabs and focus on my productivity.
These days you have chromium based choices too: Edge and Vivaldi, which has just become Cinamon's default browser. On Edge you can turn off title bar, for Vivaldi it's the address bar. They look quite neat that way.
They're both simple vertical tabs and not automatically organized as a tree, but to me that trikes the right ballance because I don't want to feel too confortable opening tons of tabs.
