It’s 2018 and we still don’t have a common, wide spread, OSS framework for self-updating native apps that runs on all the major desktop operating systems. And let’s not even go into app store territory...
Is that the end of the world? No, of course not. But we aren't building better tools over time--for instance, google docs is distinctly worse than the word I used on macintosh back in the 90s for all the use cases I care about. So is pages! All this software is more complex, and generally for little benefit.
Sure, some users, in some cases, may happen to use some features that are new. The pitch isn't "this is a good tool", it's "you have to use this tool to interact with others or retain data portability." Seems pretty user hostile to me.
If only some people would stop contributing to creative work you don't see the value of and distributing it for free on the internet!
At present you have
Debian and a bazillion ubuntu derivatives using a debian package. ubuntu/debian are going to have different versions of some libraries but you can package deps with your app.
Arch and derivatives have a pkgbuild. This is quite simple if anyone cares about your app your arch users will probably upload one for you to the arch user repo.
Fedora and suse have rpms. These will be similar but not identical.
3 packages and you can cover most of your potential users.
In the future you reasonably may expect to be able to distribute a flatpak and be done with it.
No one really took FHS seriously, each installation is a special snowflake with its own GUI and dynamic libraries story across Linux variants is even worse than it was on other OSes.
With modern Windows, macOS, Linux, iOS, Android, I'm going to have to run around for ages figuring out how to sign my packages. Despite what you might say, it's never easy or pleasant.