I installed p7zip. But discovered afterward that the built-in compress tool (engrampa) simply disappeared from the menu. It also mean that the 'Compress' shortcut (right-click) when looking at documents in the archive doesn't show anymore either.
If reinstalling engrampa from Software the 'Compress' shortcut doesn't reappear. P7Zip still works though.
Just questions which may be useful to others:
How does one achieve the Compress shortcut to reappear in the archive options ?