Snaps sound good in principle and aren't a horrible solution when they work, but despite the tagline ('Snaps are universal Linux packages') it's not clear that they work well outside of Ubuntu: they aren't sandboxed unless Apparmor is present, and despite their touted 'universality' have a hard (and unnecessary) dependency on systemd.

At this point, Guix and Nix seem the most promising for cross-distro packages.