Some platforms and environments don't have pip handy, or you might not have root access, or you can't install new software for any number of reasons, or the required libraries are not installed. curl and /bin/sh and openssl are more universal, so it's good to be able to do what you need to do without resorting to installing software.

Even if the script itself is not "practical", it's very informative. It makes it quite simple to translate into another language for the times when you don't want to shell out to another process.

I found this script a couple weeks ago and was very useful for the minimal docker image I was creating. In some cases you have certain constraints when accessing s3 and this script is helpful in those cases.