The technology for this has existed for 20+ years and is actually fairly common. It’s often referred to as dynamic range compression. I think the chief complaint here is that it needs to be more accessible. Pre-applying it would mess up too many use cases.
I think it’s just to stop the prongs from scuffing other things in the same package compartment. Usually you’ll get the cord in a bag or with the plastic but not both. With the cord is in a section of the packaging with other items it keeps them from getting scratched.