If you can boot faster than the screen can come to life, you don't need to be faster. IoT and servers might not have screens, so this doesn't apply to everythin

If you can boot faster than the screen can come to life, you don't need to be faster. IoT and servers might not have screens, so this doesn't apply to everything, but for devices with screens, just beating the screen warmup is good enough to feel like immediate startup. Also, for devices that require user authentication, such as logging in to an account, if you could offload the authentication (such as fingerprint or other biometrics) to something out of the OS itself (ROM routine that starts up with a 0 in a certain memory address and changes it to 1 on authentication), you could be booting up the OS in the background while you take a second or two to log in, and if the OS can get up and running by the time you log in, the OS can pretend that it started up immediately and was the thing that logged you in. For many devices, there is need to boot up in less than a second or so to seem as though boot up was instantaneous.