To better understand why we can't just load a snapshot of the "desired" memory state directly from a cached image, we have to understand what the OS actually does during it's initialization.

One of the main responsibilities of the OS is to manage hardware resources. During init, kernel drivers and modules perform health checks and determine availability and status of hardware resources, peripherals, I/O, etc. Since lots of things could go wrong with the various hardware components, at anytime, this process should be performed during each system boot.