https://justine.lol/cosmopolitan/

But you can't take .so files and make one "static" binary out of them.

The things I know of and can think of off the top of my head are:

1. appimage https://appimage.org/

2. nix-bundle https://github.com/nix-community/nix-bundle

3. guix via guix pack

4. A small collection of random small projects hardly anyone uses for docker to do this (i.e. https://github.com/NilsIrl/dockerc )

5. A docker image (a package that runs everywhere, assuming a docker runtime is available)

6. https://flatpak.org/

7. https://en.wikipedia.org/wiki/Snap_(software)

AppImage is the closest to what you want I think.

https://appimage.github.io/appimagetool/

Myself, I've committed to using Lua for all my cross-platform development needs, and in that regard I find luastatic very, very useful ..