The translucent menu bar is not the only controversial user interface choice in Big Sur. The greatly increased spacing between menu bar items (the icons on the right of the menu bar) also puts space in the menu bar at a premium. You may well not want to give over that precious space to Boring Old Menu Bar.
It is possible to reclaim that space by getting Boring Old Menu Bar to hide its icon.. but of course that also makes its interface inaccessible.
The solution I have found is that you can hide the Boring Old Menu Bar icon by:
Hide Menu Bar Item
in the menuThe menu bar will disappear immediately and it will only re-appear for 10 seconds every time the application is relaunched.
Now that you got rid of the icon, how do you get it back if you need to make a change in the UI?
Well you need to quit and relaunch Boring Old Menu Bar, but as a dock-less application, it does not show up in the Force Quit dialog, so you’ll have to quit it from the Activity Monitor:
Utilities
sub-folder on your Applications
folderActivity Monitor
Boring Old Menu Bar
in the listQuit
in the View
menuThen you can relaunch Boring Old Menu Bar:
Boring Old Menu Bar
in your Applications
folder and double-click itYou now have 10 seconds before the icon is automatically hidden again, to disable the hiding:
Hide Menu Bar Item
When you’ve finished you can re-hide the icon in the same manner.