The `/bin/bash` on macOS is severely out of date. So a script that starts with `#!/bin/bash` will be unable to use a lot of features. If you only rely on `/bin

The `/bin/bash` on macOS is severely out of date. So a script that starts with `#!/bin/bash` will be unable to use a lot of features. If you only rely on `/bin/sh` the user has the flexibility to point `/bin/sh` to whatever shell on their system is fastest and most up-to-date (e.g. `/bin/dash` is a pretty good choice for performance).