The hard truth is OSS is often chaotic as there is no authority saying a given API is "good-enough" to version freeze, and it limits how much individuals can integrate without upstream source-tree contiguous-integration at the mercy of 150k devs whims. =3
Flatpacks are great. I've barely ever had a problem with them, and the problems I did have were solvable with a cursory web search. Yes, they take up more space. That's a worthwhile trade-off in exchange for actually working.
This only tells me you have no idea how distributions work. The distributions themselves decide what kind of artifact they want to get out of building the software. The developer of the application cannot know that by definition because there is an unbounded quantity of distributions out there.
The only thing the application developer can do is provide a solution that works everywhere or provide a solution that helps with customized builds. There is no solution that both works everywhere and is customized everywhere.
Packagers do try to coordinate distro release cycle mess, but ultimately long term support for complex programs is tied to the OS version constellation in upstream builds. Thus, the users are going to experience the Beta stage of that code... even though people often assume a polished release-candidate isn't just a euphemism for public Beta.
Thus, the assets needed to maintain a projects function are likely to stop working within 3 years or less. Indeed, some parts of the ecosystem are worse than others.
Low attention code creates 2 paradoxes:
1. new versions may not be supported on newer OS releases due to API mutation, and old dependency injection
2. versions may not be back-ported due to old releases missing API features, and new dependencies
I think it is hilarious people make up silly stories like it is not a fundamental constraint/liability in FOSS. The situation is not anecdotal, and reaches deep into the kernel driver areas. This is why we can't have nice things, as a billion conflicting use-cases is just a chaotic ecosystem. =3