>How many Ubuntu users have custom software sources enabled; how many of them are installing games from Humble Bundle that come as their own `deb` packages with statically linked assets?
I don't have an answer to this question, but I would never do this. If the game was open source, I would rebuild it to be dynamically linked, and then publish the dynamically linked package.
If this is genuinely your philosophy then Flatpak isn't a real problem for you because you can take any OS application that's bundled with Flatpak, rebuild it to be dynamically linked, and then publish the new package using whatever package manager you prefer.
