Since basically everything I assumed in this article was false, I am not going to waste your time and will link all of the updates first.
To set the story, I was impressed by a package manager called pnpm, which competes with Yarn and NPM itself. It is a cool project, but for reasons other than I initially assumed. I’ll leave my original article in the end, just to show how confused and naive my initial post was.
Update 1: Yarn also creates a cache
yarn cache dir
yarn cache ls
Update 2: Pnpm creates hardlinks, not symlinks as I originally thought. From ln man page:
By default, ln makes hard links. A hard link to a file is indistinguishable from the original directory entry; any changes to a file are effectively independent of the name used to reference the file. Hard links may not normally refer to directories and may not span file systems.
... read the whole story at medium.com.