Peace brother, and thanks for the review, however I think your first terminal-output comparison is a little bit faulty.
When using MingW, sometimes there is actually output, but you cannot see it happening (perhaps some Windows bug with TTY?). You say NPM is sleeping, but it's actually working, and outputting logs, although the MingW bash is not outputting anything. If you ran both npm and yarn install in a standard cmd, or powershell window (or bash on WSL) you will see that they are both working, and outputting data at the same time (not sleeping). I have encountered this annoying output flaw with many other things using MingW bash, not just NPM :D; sometimes it just doesn't output anything until the very end.
Another thing maybe you can reference is that yarn was only 1 second faster than npm on a clean install of create-react-app. Maybe you can demonstrate deleting the node_modules directory of both projects, and then running install command again to show how much time yarn saves!
Thanks again for the video. I wanted to make sure that yarn actually is caching package versions locally.
Since npm 5, most of the things your mentioned have changed. This was 4 years ago! Seems your didn't research properly. Also, Facebook doesn't manage yarn anymore, since s long time ago.
Nice man, thanks for nice review.