Vagrant is my safety hatch, in case Docker goes under and aspect of it that's "the best centralized, cross-distro, server-oriented Linux package manager repository around" is, at least temporarily, thrown into disarray. Back to picking a distro and contorting it into what I need, in that case.
And it's still better than Docker if you're really in a hurry and need to get some pile of undocumented shit running locally ASAP.