Just looked at my device list and realised that about 40% of my devices comprises virtual devices, linked to a bunch of external (to HE) systems and realised that if I'm ever out of commission there'll be no one in the family to manage all this stuff and it's not even that complex.
Same here. The son in law knows what switches need to be rewired for manual operation and I made a list of things that won't work anymore when they shut down the hub and bridges.
Funny, I think about that from time to time as well. Most of my stuff is controlled via z-wave physical switches, but I seem to be adding more and more rules and automations since I've added HE. Today my wife had to ask me to turn on the Christmas tree.
Nothing really complex to someone who understands all this stuff, but I don't know where anyone would start if they came in here cold and tried to figure things out.