>We've built systems that are very fast, but almost no one knows why they are fast

It's pretty simple, all code can be modelled as a fluid flowing through a landscape. i.e. imagine a river (which represents code), it courses over the land and there are "cliffs", rocks and hills (representing bottle necks/loads).

The reality is as bus's got wider and transistors were able to be packed closer, it just allow for more water to flow faster. There's no big conspiracy at all. Because software ultimately can be expressed as a circuit.