That's true. The other dependencies of an application are handled as well, but abstractions are leaky. Storage (and file system uids), networking, are all elem

That's true. The other dependencies of an application are handled as well, but abstractions are leaky. Storage (and file system uids), networking, are all elements of the outer system that inevitably leak in the container. Using just Docker does not save you from having to deal with those, and IMHO, those are the really hard problems.