"Every" package manager? Hardly. You tested three common ones and called it a day. That isn't "every," it's a sample size of three.
Comparing pacman to dnf in a vacuum is lazy. They are tethered to their ecosystems; a real analysis would categorize them as "best for Arch-based" or "best for Fedora-based." Declaring a global winner based on syntax length is a failure of logic.
Finally, ignoring Nix entirely proves you haven't done the research. For anyone valuing reliability and reproducibility, Nix is objectively superior to these imperative tools. Next time, lead with "I tried the three most common ones." Accuracy is not optional.