You can have a much more conventional package manager without pre- or post-install hooks. One ex-Debian developer created such a package manager as a research project, presumably to prove a point to other Debian people with the same head-in-the-sand attitude about the state of Debian's package tooling.

It doesn't require the same kind of patching as Nix does (although sometimes patching does help avoid requiring those scripts).

Check it out: https://distr1.org/