QED wasn't totally original, we obviously needed some earlier knowledge- like say about the photoelectric effect, black body radiation, and Maxwell's wave theory of light. Maybe the conceptual jump to QED was bigger than the jump to lasers and so maybe it is fair to say that we haven't has a big a breakthrough since. But I'm not sure what justifies putting a very small set of breakthroughs in a special category and only counting those. Is there a long enough list of breakthroughs as big as QED to even justify looking at the frequency with which they occur?