Bug#33991: Automatic library install/deinstall
When I cleaned up my disk of stale files, I found out that I had just
about 100MB of unneeded libraries floating around, and thought it would be
nice if dpkg could remove all the libraries that are no longer needed
together with the package I just removed.
My suggestion on how to achieve this would be a new installation request:
"Install if other packages depend on it, remove otherwise". This could be
the default value for just about any package starting with lib*, because
they seldom add functionality to the system by themselves. Of course, the
user should be able to explicitly request installation.