With the option to disable the ribbon menu outright, the left sidebar toggle button has now become a moving click target — needlessly switching its position between the sidebar and workspace. This has long been the case with the right sidebar, and how its button moves every time it opens and closes (unless the window frame style is set to ‘Obsidian frame’).
Permanently affix these buttons to its respective corners.
I suggest that these buttons be moved under titlebar-button-container (the same ones holding the OS min/max/close buttons), if not a new and similarly anchored <div> class. Below is a proof of concept of just that.
I felt the same way plus wanted to hide the ribbon when the sidebar is closed, but show it when the sidebar is visible. So I added this bit of JavaScript to a script I have set to run when Obsidian starts up using QuickAdd.