This (vertical tab view) was something changed upstream in Chromium a while back but we kept it in Brave. When Chromium 99 came out, the view was removed completely and we had to make the choice between supporting it ourselves entirely (non-trivial) or removing the feature as well.
I believe there are still discussions about re-implementing this view and/or adding alternate view options in future releases. That said, none of this is guaranteed. I’ve asked our Android team to see if there is any other work/considerations surrounding this and if so I’ll be sure to reply here with what I can.
Appreciate everyone’s understanding.