Would have been great for 3.4 but I guess it's too late now :)

When one runs the debug:container command, the list of public services is displayed.
If the --show-private flag is passed, private services are displayed also.

This logic is build on / suggests a false assumption: that public services are more for "userland", while private services are more "internal". This is completely wrong. Of course, the confusion comes from the word "private", that convey this semantic when applied on classes.

I think we need a new semantic that would allow devs to discover more easilly which services/aliases they can reference or type-hint for (when using autowiring), vs which services are more internal and are not meant to be referenced.