Congrats. Now you know why distrobox is so good. The package manager of the host doesn’t matter anymore. Nix package manager also works on any system. And finally, nowadays you use flatpak to install apps whereever possible.
You can’t take the package manager as a reference to judge which OS is better.
Arch is not only about installing but keeping up to date. A normal person does not want to read about selinux. Debian doesn’t use it either but uses something comparable. On arch you have to take care of it. On debian the maintainers take care of it.