Yeah, but oftentimes loads (e.g., A/C or cooking) are not shiftable. And since there's no "EPA drive cycle" for TOU pricing or marketing standards, everybody quotes the lowest-possible rates that aren't representative of your marginal cost to consume. It's really anti-consumer.

Imagine if everything adopted this model. Gas at the pump changes price mid fill-up. You'd fret that you'd be gouged for a million dollar gallon in the moment that you glance away. Or if there were TOU in addition to data caps on your internet connection - streaming a movie might be more expensive than you bargained.

So yes, in principle I agree that pricing everything to the most-granular and timely degree is economically correct, but it's also absolutely exhausting as a consumer. There's only so much cognitive burden to be tolerated. At some point apathy takes over.