Comment by mindslight

Furthermore, the issues given for nixpkgs are actually demonstrating the success of using git as the database! Those 20k forks are all people maintaining their own version of nixpkgs on Github, right? Each their own independent tree that users can just go ahead and modify for their own whims and purposes, without having to overcome the activation energy of creating their own package repository.

If 83GB (4MB/fork) is "too big" then responsibility for that rests solely on the elective centralization encouraged by Github. I suspect if you could go and total up the cumulative storage used by the nixpkgs source tree distributed on computers spread throughout the world, that is many orders of magnitude larger.