Building huge compute clusters definitely provide an economies of scale, and can certainly reduce the cost of CPU, but it's a one-time fix. After a certain size

Building huge compute clusters definitely provide an economies of scale, and can certainly reduce the cost of CPU, but it's a one-time fix. After a certain size, doubling the size of your datacenter doesn't have much if any reduction in cost. Large modern data-centers have certainly added a few years to Moore's law as far as perceived performance, but they will also run up against a wall. In fact, the very emergence of large data-centers (as well as the rise in popularity of ASICs) are likely a response to the slowing down of Moore's law.