That's the kind of just-in-time thinking that's one unfortunate dice roll from plunging people back to pre-industrial levels.

So what if we roll another Eyjafjallajökull in one part of the world, simultaneously with a war breaking out in another, and some large-scale maintenance ongoing in another part still, while everyone's grid is designed to keep "oh half a day's tops" and not a watt more, because ain't anyone gonna pay for it? With globally reduced capacity for, say, a week, that "half a day's average demand" worth of storage may start running dangerously low, and what then? Will we somehow scramble to fire up long-closed fossil fuel plants in that time?