Technology is more complicated than even a few years ago. It can do more. It is accessible to more people (and all of their unique needs and abilities). Computers have the ability to make an almost infinite number of interconnections with other computers.
The point is that a single person can't possibly keep track of a sufficient quantity of information to direct a sufficiently complex system anymore. And with the communication and development tools available today we are able to build these complex layered solutions without always having to worry about all of the other details that we can't possibly worry about.