Intel chips have basically stagnated for about 5 years and they abused their monopoly and market leader positioning by offering marginal improvements each year in order to protect margins, as well as fab shrink problems that insiders describe as coming from culture not dissimilar to Boeing; just with less lives at stake.
In the meantime, competitor foundries have caught up, and exceed Intel's ability to ship in volume. ARM obviously is eyeing the desktop, but more critically server market so the latest ARM IP is geared towards higher performance computing, quite well I may say.
State of the art fab + state of the art processor IP = state of the art processor. Not a huge surprise :)