[Unman]

I guess I do not understand the manner in which you use "ad hoc" to refer to package management.

It seems as though you are now talking about cross-distribution package management. It is further confusing that you are contrasting all "Linux" to the single distribution macOS.

To me the term is "ad hoc" current w.r.t. NixOS , GNU Guix and other purely functional systems, and there the distinction is made between:

1) declarative -- in which a rebuild of the system will ensure the package is present and configured as expected; and

2) ad-hoc -- in which the user can affect all of the system with side effects and rebuilds will not result in the same state.

Why would you want to allow users to randomly and aribitrarily affect all of the system and end up in an unknown state? Isn't that exactly what curling shell scripts achieves? And what method does macOS implement in order to avoid this?

If all you're talking about is cross-distro package management then you and your users can either give up on this and standardize on one OS and just pony up the cash for RedHat (same as you do for macOS) or else start writing Flatpaks.