I understand the instinct but if people seriously think that they are solving any problem by unplugging cell phone chargers, they are simply bad at math. Human time is easily worth more than that, even when working at minimum wage.
That said, it obviously sucks that utility prices are rising for people who can not effortlessly cover that (not to speak of the local pollution, if that's an issue). Maybe some special tax to offset that cost to society towards hyper scalers would be a reasonable way to soften the blow, but I have not done the math.
They are not necessarily bad at math, but they probably aren't electricians or EEs or have ever needed or been asked to calculate how much power a cell phone charger uses.
Mom/Dad used to unplug things and turn lights off, so they do too.
I think it's also just how people start acting in situations where they can't control anything that would make a difference. In the presence of an issue you can't solve, if you can do something, even if it's small and won't really help, sometimes it feels good to at least do that. Being able to address the anxiety even a little a bit still might be worthwhile.
They don't know it doesn't help. That's what you're missing.
How many paid hours do they get? Human time isn't fungible with paid hours.