AndroidCentral explores the supply situation and says that even though Google spend tens of millions of dollars to advertise the Pixel phone, its supply chain system just isn't up to the task of meeting the global demand:
For all of their flaws, the other Android manufacturers know how to manage a supply chain. Samsung, LG, Huawei, Motorola, HTC and heck, even OnePlus now, know how to make phones available around the world in massive quantities. They have in most cases each made the necessary deals and commitments to get the phones in thousands of physical stores as well, a dramatically taller task than simply stocking a couple of warehouses for online-only distribution.If Google has bigger ambitions for own-brand phones, the company will need to sort out this problem before future launches.