I recently changed my Ubuntu 18.04 window manager from Mutter (Gnome Shell) to i3-gaps. Some of the unexpected things that happened:
- polkit-gnome-authentication-agent-1 doesn't automatically start
- synaptic touchpad settings are different
- media-keys aren't functional
If I type
wmctrl -m into the original default configuration, it returns Gnome Shell. This suggests that any loss of functionality is due to Gnome Shell as a whole as opposed to just Mutter.
I have several questions regarding all of this:
1) Why isn't replacing Mutter with i3 as modular as one would naively think? Did installing i3 remove all of Gnome Shell's supplementary functionality?
2) Will I further encounter any other side-effects that can't be explained by referring to the functions of Gnome Shell?
3) I know I can modify a whole bunch of configuration files to reinstate certain functionality, but is there a more coarse course of action I could take (say involving gnome-sessions or the gnome-setting-daemons)?