Nix - is fast (faster than Homebrew or Docker) - is multi-user (don't need root privileges to install software) - lets you try software without permanent

Nix - is fast (faster than Homebrew or Docker) - is multi-user (don't need root privileges to install software) - lets you try software without permanently installing it - gives you fast, reliable undo without requiring a special filesystem - lets you automatically (re)produce a setup that never drifts from its official definition - can safely perform upgrades and configuration changes without thinking about what has been done to the system or environment in the past - has tons and tons of software already packaged for it at this point, which you can just use without any special effort