"There will still be occasional differences between distributions. These are things you can work around. It may be painful at first but it will be worth it: you will provide a much superior user experience by working around the issues with your users’ libraries rather than attempting to replace them."

Sure, like it was happening 20 years ago, and we still had apps break ALL THE TIME when the user just upgraded to a new distro version or when she changed her distro. It's simply not scalable. It has already been tried. Sure, the flatpak world is not perfect, and I would never choose this option (maybe I like snap better), but it's a step in the right direction.