Traditionally; definitely. But if the purpose of package managers is to acquire packages fit for use with the distro, then the position of alt packaging formats (e.g. Nix) and/or solutions that make use of container technology (e.g. Distrobox) at least provide some food for thought.
Like, if I choose to install Debian (Stable) and openSUSE Leap and then proceed to install all my packages through distro-agnostic ways accessible on both distros (e.g. Flatpak, Brew, Nix etc.), then wouldn't you agree that these systems become remarkably close to one another?
Hats off for the efforts provided by maintainers. But I feel as if that potential should be better utilized (in part) to achieve greater goals.