The whole idea of pirates wearing eyepatches seems simply the replication of one particularly colorful pirate archetype over centuries of literature and tales.
Stereo vision is helpful on ships (and allmost everywhere else where you need eyes), even when not boarding.
Just a thought
But I know I am worse doing climbing etc. with one eye.
It is probably something you can train and get used to, that it is not such a big deal, but I cannot imagine doing it on the same level one eyed.
But that’s much more interesting…
It's amazing how much of our conscious experience is hallucination, and yet a lot of people are disparaging LLMs for doing just the same...
Optical illusions are evidence of the pile of hacks that our senses and our consciousness use to make sense of the world. I think it is really difficult to fully disengage from the biases this induces, and we are sadly best at perceiving such flaws in others. This might be one of the reasons why humans have to socialize with other humans to maintain mental health.