Seeing as iPads are basically iPhones with much larger batteries, and don't suffer from the same issues, I disagree.

This could have been avoided if they weren't so obsessed with thinness. I reckon that if it was thick enough to not have a camera protrusion, it would be the perfect balance of form and battery life.

A larger battery, running the same CPU, with the same stated "battery life" as the original battery, will degrade gracefully for a longer period of time before the compute performance must also degrade.