It takes a while (think like 10min+) to reboot these planes. Checkout "cold start 777" on YouTube [1].
There are a ton of computers (FADECs for engines, fuel management computers, FMS (flight management), PFC (flight computers), weight and balance computers... and much more). All of these have state. Which way is up for the gyros. Proper direction for the compasses. Proper location on Earth for the navigation system... etc. Basically, a 777 has the mother of all POST sequences, so frames in line operation are rarely restarted, for operational efficiency.
Reminds me of the navigation systems for some rockets (Atlas, IIRC), that require 24 hrs sitting level on the pad to fully initialize their starting ground state (super precise gyros). This ain't like restarting your internet connected juicer.