"Last year's phone"

What? How can that be? Are you using your phone with the display on constantly, while still using nearly zero CPU?

Have you actually tested this, or is it just an intuitive assumption? If the former, what kind of screen does your device have? If the latter, your intuition is incorrect.

Unless I'm using the power-guzzing Google navigation, 'cell standby' is always at the top of my battery usage list, followed by 'phone idle', followed by 'Wi-Fi' if I've had it enabled, usually followed by 'Android system', with perhaps a few other entries, and 'display' dead last - and that's if I've had it on for the hour or so that it takes to even show up in the list (I think there's a threshold of 1 or 2 percent).

If I do nothing after unplugging the phone but tap the screen every now and then to keep it on, 'display' will go up to 20%, with 'Android' system in the 60s, so if that were more efficient it would have a substantial impact on battery life (although in the real world case 'cell standby', 'phone idle', and 'Wi-Fi' tend to come to around 90% of the total battery use).