There are enough extensions to do whatever you want. My Gnome desktop has no top bar. Activities are totally hidden: I don't have any mouse or keyboard event th

There are enough extensions to do whatever you want. My Gnome desktop has no top bar. Activities are totally hidden: I don't have any mouse or keyboard event that shows them. I use 5 virtual desktops and switch between them with hotkeys. I have a bottom bar with status icons, task bar, application menu, a menu of bookmarked directories, a menu of the last notifications, a menu of recent files. Notifications popup from the bottom. I alt tab between windows on the current desktop. Possibly other stuff but that's the most I can remember. If I remember well I stayed with Gnome Fallback until there were enough of those extensions to rebuild my desktop with Gnome shell. That was about at the time of Ubuntu 20.04.