@mohamedsalah It works practically on the smaller laptops. If you are working on a big screen and you are developer or have big screen at home - yes expanding the vertical tabs and sidebar and keep everything open works well.
However when I go to office or on the move while using my 13itch laptop - keeping the vertical tabs open takes so much space! Hiding them and opening them adds an extra click each time which is annoying.
I used to use Atlas before and absolutely loved how they made vertical tabs autohide when you just hover on it. Worked weel on my big screen and on my small company laptop.
And another thing to note is the sidebar - if you have vertical tabs enabled, the sidebar can go away really its not needed.