I still don't get the whole #flatpak thing (vs static + dynamic linking). It all seems so difficult and complex. Why not just...

• want a specific version of libfox? -> statically link libfox v6.9
• want per-interface permissions? -> make a new dynamic linker that prompts the user, "do you want to allow this app to access libfox? yes/no" OR have the linker read declarations at package time (allow/deny/ask).
• want a unified api? -> make a new shared library

(1/?)

• want per-file/resource permissions? -> have an interpreter or libc that implements open() et.al. to either ask the user, or reads the declarations made at package time (allow/deny/ask).

Also, #flatpak requires the OS to implement the flatpak runtime. Got a new OS (/distro/DE)? Well now it has to implement the flatpak and dbus apis before flatpaks work, instead of just relying on individual shared libraries.

(1/2?)

@foxxy other things you said:
* hard linking: yes, AFAIK this is what #AppImage's do. In Essense you get many big binaries, also not ideal and would waste space. #flatpak deduplicates such stuff.
* share libs are of course always made, The problem is that distros adapt it, have different versions and sometimes things break. Testing against one target is just way easier and more like devs are used to nowadays.
* flatpak runtime? Yeah, but 90% of distros have it. If not, it's 1 thing to install.

@rugk Somebody else who has now deleted their comment enlightened me to the fact that Flatpaks do a few things well:

• "Static lib" dedupes - implementing it as I propose is difficult and problem prone, Flatpak-style containers will always do it better
• Anti-hysteresis: for apps that have multiple executables, Flatpak-styles handles hysteresis gracefully.

Among other things, I'm still really upset that Flatpaks reversed certificate progress for me by years, for not enough benefit to offset.

@rugk For my concern about having to create a new Flatpak runtime for a new OS/distro/DE, I was assured that the Freedesktop runtime has few/no dependencies, so it should provide Flatpak support out of the box even if it doesn't integrate well - which is fine, since in this hypothetical a new OS/distro/DE is being made, so we can live with that, plus it could provide a foundation for the developer(s) to modify incrementally as they have time. I have no way to verify this though.