Thing is, though, there's nothing really stopping devices from having a middle ground: have the device persist the firmware, and only have the kernel feed the d

Thing is, though, there's nothing really stopping devices from having a middle ground: have the device persist the firmware, and only have the kernel feed the device a new version of that firmware if actually needed (e.g. because there is indeed a newer version of it). Ultimately, though, the device enumeration and initialization is a tiny fraction of the startup time on most computers, be they desktops, laptops, servers, phones, tablets, or what have you. Usually the actual source of long startup times is the incessant need for these machines to spin up oodles and oodles of background services doing who-knows-what, and it's remarkable how much faster a machine boots when these services are pared down to more reasonable minima. And worse, it's these background services that often make modern computers feel so slow even after they're booted up.