It's pretty handy for things like being able to just say "hey Google, unlock the door" when I'm carrying a dozen bags of groceries.
I use automations as well, but sometimes I need something done outside of my otherwise-considered parameters. And it's easier to just yell your wish into being than to take out your phone, open an app, select the device, then pick your command.
The fleet of cars is summoned back to the HQ to have the update installed, so it causes a temporary service shutdown until cars are able to start leaving the garage with the new software. They can't do major updates over the air due to the file size; pushing out a mutli-gigabyte update to a few hundred cars at once isn't great on the cellular network.