Henry Samueli, CTO of Broadcom, makes the same point about Moore's Law. As the feature size of successive chip generations decreases, the cost of the manufacturing technology increases. And the techniques needed, such as FinFET and other 3D technologies, also slow down and increase the cost of using the manufacturing technology:
Process nodes themselves still have room to advance, but they may also be headed for a wall in about 15 years, Samueli said. After another three generations or so, chips will probably reach 5nm, and at that point there will be only 10 atoms from the beginning to the end of each transistor gate, he said. Beyond that, further advances may be impossible.Both of these are simply applications of the Law of Diminishing Returns.
"You can't build a transistor with one atom," Samueli said. There's no obvious path forward at that point, either. "As of yet, we have not seen a viable replacement for the CMOS transistor as we've known it for the last 50 years."
... the ongoing bargain of getting more for less eventually will end, Samueli said. "We've been spoiled by these devices getting cheaper and cheaper and cheaper in every generation. We're just going to have to live with prices leveling off," he said.