Intel has the best process technology bar none. 14nm CPUs is quite astonishing.
Intel made a big mistake with the Pentium 4 because they thought that dumb would be good enough when they got the clock up to tens of GHz. They found out that clocking Silicon much above 4GHz wasn't do-able, and AMD almost gained the lead by doing a much smarter CPU design (ie, using the available transistor count to accomplish more useful work) despite having to implement it with an inferior process technology.
Intel resurrected the Pentium 3 and worked on it. They got back level with AMD, then overhauled them and stayed there. AMD doesn't appear to know how to do smarter squared (nor does anyone else). It may be a software problem, not hardware: how to automate code generation for very many cored CPUs. Which ARM could make tomorrow, but they presumably know that 128 one-watt cores on one chip wouldn't sell. Heck, NVidia make them, but GPGPUs running CUDA code just point at the problems in using that approach more generally.
My theory is that Intel could put AMD out of business but never will, because it needs to point at AMD to justify not being treated as a monopoly (and maybe to stop itself behaving too much like one!). If the only place to buy high-power workstation and server chips was Intel, they'd end up being regulated as a monopoly, and then innovation at Intel would cease.
Maybe one day ARM will be competitive outside the mobile and low-power arena. Time will tell. Until then, Intel is top dog.