* Try Nix on your distribution [1], package may be already there [2]

* Create package for your distribution, become maintainer, that's not the last time you need it

* Switch to less outdated channel, other packages would be fresh too

* Change distribution

Flatpak has its niche but your use case looks like fixing broken distribution. There is no package, package is outdated, it is hard to make package, it is hard to publish package - these problems already solved.

Hard problems may be

* I want several versions of the package

* I want entire environment like it was 6 years ago so I can run / compile application (in parallel with current)

* I want to run application in sandbox - no network, no file access, no mic etc

* I want proprietary application and they don't play well with Linux ecosystem

Hope Flatpak will address them while keeping security in check.

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Debian Sid is claimed to be not more unstable than Arch [3]. And I had less problems in a decade than a single Ubuntu dist upgrade. Rolling release does not accumulate breaking changes. Run update once a week and you'll be fine.

[1] https://nixos.org/download.html

[2] https://search.nixos.org/packages

[3] https://linuxconfig.org/how-to-run-debian-sid-relatively-saf...