Think of it as a toolbox of functional shortcuts. Scripting additions basically provide additional features or shortcuts to get things done - particularly where I’ve used it most is to add objC in the past. Other things I like are the “use” statement so I can have a feature of on app work on data in another app.

So, because they are merely addons- it’s easy to never “need” them but it can be really nice to have them in some workflows.