Why do you want to stay within the .deb ecosystem?
The difference between .deb and other common packages (rpm, pacman) are minimal. Almost all desktop distros will handle dockerfiles just as well as Ubuntu.
I'm fairly satisfied with it, honestly. It's prevalent and 'standard' enough. People run Ubuntu/Debian more than .rpm based systems I guess. I'm just trying to stay as near as my Docker deploy targets as I can.
The difference between .deb and other common packages (rpm, pacman) are minimal. Almost all desktop distros will handle dockerfiles just as well as Ubuntu.