> 1. For JS projects at least, you still need to npm install or yarn install for all packages. This can take a bit of time.

I believe that's the problem pnpm is trying to solve (err, not the time part, I can't swear it's wall clock faster, but the "hey hard links are a thing" part <https://pnpm.io/faq#:~:text=pnpm%20creates%20hard%20links%20...> )