How about why there have not been any major scientific advances over the past 100 years? This would be massive ground breaking stuff, like the development of electromagnetism into a viable commodity (radio, video, lasers, electricity, electric motors ...). Or the application of the atom into a useful tool.
The stuff we have today is refinements of stuff that was first discovered in the 19th and early 20th century. Why haven't there been new, fundamental discoveries been made?
Things like the microprocessor are refinements of the transistor, which itself is a refinement of the vacuum tube. Some of the key concepts in computer processing come from Ada Lovelace, who figured out stuff such as programming loops while working with Charles Babbage (the computer) in the 1800's.
That's actually worth 15+ pages, not counting the sheer amount of research needed.