The interconnect cost also skyrockets on the cores themselves. Intel's moved to a mesh network on their newest cores:
https://www.anandtech.com/show/11550/the-intel-skylakex-revi...AMD's advantage of picking and choosing smaller parts still reigns supreme. If a Infinity Fabric component on the AMD die is defective enough to necessitate it is turned off the die is no longer able to participate in some of the more complex multi-die couplings. If the mesh component on an Intel die is defective the core(two actually because SKUs) has to be fused off and the part automatically bins as a lower SKU. As the mesh increases in complexity more and more of the design can be compromised.
