Well, I'm not a mind-reader, but I'll humor your question. A charitable reading of your post is that you are refuting a hypothetical reader who might think that

Well, I'm not a mind-reader, but I'll humor your question. A charitable reading of your post is that you are refuting a hypothetical reader who might think that the point of the post is that the artist came up with the idea of a cell phone decades before such a thing existed (and was thus judging them to have extraordinary ingenuity). A more straightforward reading is that you are independently judging their contribution to be inconsequential because they didn't go on to realize the idea as a working object. Maybe you meant some third thing and hoped we'd read between the lines to find it. Regardless, my contention is that question of whether to credit the artist with inventing the cell phone is beside the point (however you come down on it), and the real interest of reading this has to do with empathizing with a century-old observation that feels relevant today, despite the gap in (realized) technology.