Those phones are made by a small number of hardware vendors on homogeneous hardware. At any given time, Google only has a handful of Pixels that it is supporting, those Pixels do not have user configurable hardware, and those Pixels are all identical.
Dell sells a PC and it has to work with any number of possible storage devices. Users might swap out the modem. It is expected to work with any PCI-E device. It supports hundreds of classes and models of devices like printers and scanners. etc. etc.
Saying that "it is used on phones" doesn't really mean much when there are only what? 5? 6? major phone manufacturers supporting a limited and largely homogeneous set hardware configurations. Same for cars; a small pool of manufacturers and suppliers on identical hardware configurations.
