I don't think Debian needs to choose. Debian will keep using deb/dpkg as flatpak and snap are not intended to replace a distro's main packaging. They are supple

I don't think Debian needs to choose. Debian will keep using deb/dpkg as flatpak and snap are not intended to replace a distro's main packaging. They are supplements so users can get newer packages directly from upstream developers. Note that Debian 9 already supports both flatpak [1] and snap [2]. Because of the way snaps/flatpaks are isolated from the rest of the system, they can coexist without issues. I thought the creators of snaps/flatpaks would be upstream developers, so they themselves will vote on the package management system by using either. There is no duplication of effort here. Myself I prefer AppImage [3], because of its simplicity and the fact that they are already supported on all Linux distributions, without installing any explicit support. [1]: https://packages.debian.org/stretch/flatpak https://packages.debian.org/stretch/flatpak [2]: https://packages.debian.org/stretch/snapd https://packages.debian.org/stretch/snapd [3]: http://appimage.org http://appimage.org