Yes, you are right on that. Direction has no meaning at all. Apart from shield termination, it doesn't matter at all.
However, we cannot assume that it's meaningless to everyone. Let me give you an example.
When USB-C was first introduced, I observed that many people esp. those who arent tech savvy were lost at how to connect the cable to their phones.. They are so used to inserting the cable only 1 way (directional connector). Now, they no longer have to do that, they do not know which way to connect. Took them a while to finally get used to it.
Another example is in factories. I learnt that standardising and reduction in time need to make decisions could speed up production process. So, if I apply it to this cable making factory. I would say workers will likely need to assemble audio related cables of different types and models. So, having a directional mark on all the cables means that workers do not need to identify which cables are directional and which are not. I believe this will make things easier for workers.