>On top of that, Linux essentially sucked all the air out of the UNIX development space by killing off all the commercial UNIXes.
For good reason too. The commercial UNIXes were absurdly expensive, and they were all incompatible with each other too. There's a reason all the software developers abandoned UNIX and went to Windows. UNIX killed itself with ridiculous license fees and fragmentation. Linux saved it by making it free, open-source, and unifying it and using common standards instead of a bunch of vendors trying to make their own hoping to gain marketshare and ending up losing everything to MS. Of course, this hasn't prevented Linux from having its own share of fragmentation (the different DEs chiefly), but it's nothing like the UNIX Wars of the 80s.
Lets start with package formats, people discuss this matter as if it were building an app for ios vs android. 99.999% of the work is the application. Package formats are just different sets of instructions for building the same source code the works ultimately on any system so long as its required libraries are present.
Continuing on with audio, virtually everyone uses pulseaudio. JACK is pretty much reserved for audio production and is its own animal.
The majority of configuration files are similar/the same, most differences are minor. For good or ill most distros are adopting systemd.
Window managers or desktop environments are just components virtually all of which are able to be run on any distribution.
No, package formats aren't just different sets of instructions, because on each distribution certain files might land on different places.
Plus someone has to keep track of those instructions for every single distribution.
Finally, supporting the same format isn't enough, for example a RPM for SuSE isn't the same as a RPM for Red-Hat.
Well, apparently you forgot there are people still using ALSA and OSS.
When doing desktop applications anyone that cares about UI/UX of the respective users wants to integrate with the menu system, notification on the toolbar, context menus, drag-and-drop of the window manager, printing,....
So it isn't just components.
Of course, if the goal is to have a plain twm experience, then forget about what I am saying.
The percentage of desktop users not using pulse is is a rounding error. Firefox doesn't even work without pulse anymore Notifications and menu systems are standardized. Printing doesn't require special work to work on different distros. Drag and drop just isn't part of what a window manager does period its more what your file manager does.
Your valid issues are pretty much limited to the fact that software must be packaged for several distros in order to be suitable for distribution on even most systems and file manager integration is still something that requires you to integrate with gnome AND kde to support most users.
For good reason too. The commercial UNIXes were absurdly expensive, and they were all incompatible with each other too. There's a reason all the software developers abandoned UNIX and went to Windows. UNIX killed itself with ridiculous license fees and fragmentation. Linux saved it by making it free, open-source, and unifying it and using common standards instead of a bunch of vendors trying to make their own hoping to gain marketshare and ending up losing everything to MS. Of course, this hasn't prevented Linux from having its own share of fragmentation (the different DEs chiefly), but it's nothing like the UNIX Wars of the 80s.