Hi, English isn’t my mother tongue so I was asking myself that question since I first encounted a w/… Back then I was like: “What tf does ‘w slash’ stand for?” And when I found out I was like “How, why, and is it any intuitive?” But I never dared to ask that until now
To be fair, no living language is.
French is heavily managed by the Académie, I guess it depends how you interpret “designed”. English is a much freer language that morphs and absorbs terms from many languages.
I wonder how much of the managed-language sticks vs the emergent-language. I recall years ago there was news of how the academie made up their own word for email.