[333c]

On the other hand, a capacity in mAH is not the only spec about battery life they should provide. Each new phone tends to consume more battery, due to new processors, bigger screens, or other factors, so an indication of typical battery life is useful.

[GFischer]

Not always. The newer Qualcomm chips consume significantly less battery due to changing to 14nm and 10nm processes.

Switching to OLED (as Apple did) also increases battery life.