The problem is that it does not manage and version dependencies for you. Say I start a new C++ project where I want - say - use ZeroMQ and also Folly to parse JSON. Where do I start? Should I install ZeroMQ and its headers globally? What if the version changes? Will it conflict with other system libraries? Well, better start using Docker. What if the version I need is not in the Ubuntu repositories yet? I need to add to the dockerfile instructions to download and install the dependencies... you see, things get out of hand real fast