Are you sure it's just to annoy you. Lots of people use laptops nowadays. They might be forced to go offline to use ít elsewhere.

Just sayin', because that was the case with me for the three years I attended college. It didn't matter if people were at 99.9%. Once I had to log off or be late for school or I was meeting up with schoolmates to do work, I logged off.

And just to add to that... I live in a suburb where the power goes out often. Losing power for 2 hours or more ~ once a month is pretty normal & little outages of 10 minutes to half an hour every so often (sometimes twice weekly, sometimes only happens every couple of weeks).

So in my case, I'd just vanish from the network & it would have nothing to do with me making a decision to disconnect.