KDE contributor Markus Slopianka sought to clarify the adoption of Flatpak vs. Snap in modern Linux distributions. He looked at the state of Snap and Flatpak in the releases of Arch, Debian, Fedora, Gentoo, Mageia, openSUSE, and Ubuntu.
He found that generally the latest Flatpak version was available on all of the latest distribution releases. However, he found that Snap was only using the latest version in Ubuntu 17.04 Zesty and Debian Stretch. Snap support in Ubuntu was out-of-date, Fedora doesn't have the support in the main repository on F25, the Gentoo Snaps were outdated, the openSUSE support was outdated, and on Mageia the support wasn't even available.
Slopianka wrote on his blog post, "given these results alone, I’m quite frankly pretty puzzled how the jury could still be out and that’s completely ignoring the centralized nature of Snap."
He even argues that distributing apps via AppImage on Steam would make more sense than Ubuntu Snaps due to Canonical's central repository approach for Snaps, "Distributing AppImages via Steam makes more sense than Snap (Steam has the same centralized nature as Snap). Not only does every somewhat mainstream distribution ship Steam in some non-free repo, it would also allow us to distribute applications to Windows and macOS."