How does it stack up against traditional package management and others like AUR and Nix?
Flatpak is a project trying to fix many things at once
- make apps that work on every distro
- thus have apps officially supported by the devs, unlike distro packages mostly
- sandbox apps with an android-like permission system with a rating system
- use modern standards like delta-downloads, deduplication and BTRFS compression to save storage space
- make everything nice and user friendly