You still use left and right on board, but referring to other things. E.g. you sit on the left side of the table, and by using "left" it's clear that your reference is the table itself and not the ship.
What you achieve is a new set of coordinates relative to the vessel. You are going north, sitting on the port, with a glass of wine in your right hand, instead of going up and sitting on the left.
This all feels a bit like arguing against the use of cardinal directions because they don't make sense unless you learn them first.
If you use left and right for the ship, you wouldn't be able to use personal left and right without risking ambiguity. You'd just be trading one convenience for the other.
Port and starboard become instinctive very quickly, with no mental gymnastics needed. Left and right are confusing, there must be a reason all sailors are using those terms..
Tradition is a form of collective intelligence. Tradition is the ritual the Yandruwandha carry out to cook nardoo. Without that ritual it is poisonous.
No, it's just a form of long-term repetition, intelligence is not required, just don't limit your example set to those that save you from poison, but also include those that poison
So it’s not actually achieving anything. You could just say left always refers to the ship’s left.