The Software/library version incompatibility problem has always been an issue especially on the developer side. Your comment about low marketshare is a "chicken or egg" problem. Which comes first making a better ecosystem for app availability or getting companies to build for Linux.
The fundamental problem is the developer has to deal with distro versioning to this day. This is why DEBs are made for multiple versions of Ubuntu and not just Ubuntu. These DEBs might not work in Debian so more need to be made. RPMs for Fedora, openSUSE, Mageia, etc are all different so yet more pain.
This is what creates the fear of companies to devote resources to such an infrastructure, it's just way too much work to justify it.
Snaps, AppImages, and Flatpaks are VERY important to the future of the platform to gain any massive desktop adoption.
why are you writing about this in 2019? it hasn't had a release in over 5 years.