I don't know if either Nix or Guix will be stable and supported for the next twenty years, but they probably won't be ruined by corporate interests. I've personally quite enjoyed learning about functional package management, where a package is seen as a pure function whose arguments are all its dependencies, the source, and the build tools. The output of the function are the binary artifacts.

It's a good idea, and if you like the idea of setting up your computers by programming in Scheme, Guix will be right up your alley.