I was curious how many other people wished vertical tabs was mirror flipped so that the new tab button is at the top and wow, this is a very common request/complaint! I can't even link all of them here because there are simply too many

https://connect.mozilla.org/t5/ideas/in-vertical-tabs-add-an-option-to-open-new-tabs-at-the-top-of/idi-p/88898

https://connect.mozilla.org/t5/ideas/open-new-tabs-in-inverse-order/idi-p/90669

https://www.reddit.com/r/firefox/comments/1joe2uw/vertical_tabs_are_designed_to_have_the_wrong_order/

https://www.reddit.com/r/firefox/comments/1jsvqhk/how_do_i_make_the_vertical_tab_list_upside_down/

https://www.reddit.com/r/FirefoxCSS/comments/1jcysdz/move_new_tab_button_in_vertical_tabs_to_the_top/

https://www.reddit.com/r/FirefoxCSS/comments/1jr2kce/is_it_possible_to_have_the_new_tab_button_at_the/

https://www.reddit.com/r/edge/comments/m0mz4e/invert_order_in_vertical_tabs/

https://techcommunity.microsoft.com/discussions/edgeinsiderdiscussions/pinned-vertical-tabs-button-at-top-and-reverse-tabs/2077410

https://techcommunity.microsoft.com/discussions/edgeinsiderdiscussions/vertical-tabs-mode-new-tab-button-should-be-fixed-position-at-the-top-of-the-tab/4395114

https://answers.microsoft.com/en-us/microsoftedge/forum/all/new-tab-button/5a65d2d3-03e1-4912-af0e-2ac592ad2b34

https://github.com/brave/brave-browser/issues/31424

https://github.com/brave/brave-browser/issues/30884

https://community.brave.com/t/mirror-vertical-tabs-so-that-new-tabs-are-at-the-top/496225

https://community.brave.com/t/feedback-to-improve-new-vertical-tab-window-layout/490850

https://community.brave.com/t/new-tab-buttom-on-vertical-tabs-i-hate-location/494989

https://community.brave.com/t/move-the-new-tab-button-up-on-vertical-tabs/480693

https://community.brave.com/t/vertical-tabs-new-tab-button-placement-and-functionality/491304

https://community.brave.com/t/vertical-tabs-width-and-new-tab-button/490807#:~:text=Another thing that would be nice%2C is moving the “New Tab” button to the top of the tab strip%2C preferably next to the “Minimize Tabs” button

scroll bar in horizontal tabs