> System updates have been seriously optimized in the last few Android releases. They used to take like 5 minutes. On the Pixel phones Google uses two system p

> System updates have been seriously optimized in the last few Android releases. They used to take like 5 minutes. On the Pixel phones Google uses two system partitions. One is the one you're currently running and the other one gets the update applied to it in the background without you having to stop using your phone. When you reboot it just has to flip which system partition it boots from and maybe do some first boot actions. If the phone starts up successfully it'll then apply the update to the original partition to keep them in sync.