[toyg]

You make it one tool, and sysadmins will instantaneously lock it down. These package managers, in most cases, are developer tools built to get around system-wide locks on libraries; the more you centralize them, the more likely it is they will get locked down, and then someone will build tools to get around that, and so on and so forth.

[olejorgenb]

As one of the few package mangers, nix can be used without root access.