I wonder why battery life on iOS major betas are still so bad.

On the app level, Apple apps have strict power profiling. I've spoken to Apple's app engineers, and one of their biggest constraints in feature delivery is rejection by "battery police". So an app's power profile should be measured even in development.

On the OS level, several advancements like coalescing and App Nap are making the system more power efficient.

I can understand that beta builds are different due to: * debug builds having symbols and more overhead in processing * certain power profile restriction could be lifted

But those probably don't account for allowing a huge drop in battery life. Fundamentally, if the OS restrictions are strict, then any bad code should be prevented from draining the battery life too quickly. Why hasn't that happened? Or am I missing something?