It seems pointless to argue further about the “need” for a menu.
But you are a little off with the way bookmarks work when using keyboard shortcuts. Bookmarks are the first options that load in the omnibar when typing, so I don’t ever have to actually click anything. I start my day every day after opening Brave by hitting ctrl+n (or ctrl+t if I want a tab), typing 2 or 3 characters of URL of the bookmark I want to open (which auto-populates the address in the omnibar), and hitting enter. I can open dozens of bookmarks that way in just a couple seconds without clicking anything. At most, I may have to hit tab once or twice to cycle through bookmark options in the omnibar if I type something unspecific that applies to more than one bookmark. It’s extremely fast; try it sometime.
(It even works with whatever you title the bookmark–if you decided to save your email inbox URL as “blueberry” in your bookmarks, you could open it by typing ‘blu,’ hitting tab, and pressing enter.)
And I’ve never said use keyboard shortcuts to open the menu; that would be a bit silly and clearly go against my argument–I don’t hit ctrl-shift-b to open my bookmarks bar and then mouse around in it (although I will ctrl-shift-o to organize them occasionally). I’m saying you can do whatever you intended to do in the menus without opening any of them at all if you know the keyboard shortcuts. The only thing I really use my mouse for in a browser is interacting with the content within a page or moving my browser windows around on my desktop. I have the most of the keyboard shortcuts for both Chrome/Brave & Firefox memorized after years of use.
I’ll fully admit that my power-user habits run deep: I don’t even use the mouse to do things in Windows, really. (I tap the Windows key & type whatever app/program I’m wanting to open, press enter; I open the explorer by hitting win+e, task manager by hitting ctrl-shift-esc, etc.) That level of depth may not be for everyone, but the keyboard is intuitively faster even for novices. Who really prefers to use contextual right clicks for copy/paste commands instead of ctrl+c/v? If the goal is to do things as quickly/conveniently as possible, the keyboard is just about always the way to go.