The Apple stuff seems to be quite good at updating itself unattended, I can't remember the last time I manually updated any of the computers, phones or iPads, which is nice, as there are a lot of them (another MLIR, why do have so many computers, when I was at school, we had 4 BBC model Bs for 1,500 kids).
They're not left on, they're sleeping, no idea how much power that uses, apparently a 'power nap.' It can be turned off.
Apparently, the Windows laptop can do the same, but good luck finding that option. I have a mothership Macbook on backorder (we're hiring about 100 people a month, apparently I'm not at the top of the queue for IT). It's learned me that I'm too old for computer diversity.