Thank you for the answer (that is not a semantic discussion /end-of-rant) I had no idea that the London map inspired so many others (among them - the Paris one

Thank you for the answer (that is not a semantic discussion /end-of-rant) I had no idea that the London map inspired so many others (among them - the Paris one I mentioned in my question), I thought that the design was rather a typical one for maps of underground services the same way as ground maps look more or less the same (at lest in their raw design). TIL.