It only soves the problem partially. The drawback of AppImage is that it cannot package an application containing multiple executables such as Emacs. The best solution may be coping Apples' app-bundle idea. An app-bundle is just a folder containing metadata, executables, shared libraries (dylibs), text files and images. This package format can be installed by just dragging and dropping the folder to /Applications directory and
deleted by just removing the folder. The Finder file manager shows the app bundle as the application icon and allows running the app by clicking on the app-bundle folder. This idea is easy to implement on Linux, it would decrease Linux fragmentation and the work duplication
that happens when packaging some application.
I think part of the problem is that there's so many "Does x not solve this problem?" solutions now all with their own unique downsides and upsides, it reminds me of that one xkcd[0].
I spent time in MIPI PHY and I am very familiar with this issue. appimage isn't the same kind of solution though because there were zero competing solutions. There were no universal linux binaries. Having one is a much better situation.