Servicing RAM uses power. So more memory = more power consumption.

Android apps using Java, recycle released memory using garbage collection.

What this diagram shows is that garbage collectors are really awesomely fast if you have a relative memory footprint of 4 or 8.

In other words, you need four or eight times more memory, than you are actually using to be super efficient. But when the memory becomes constrained, that performance goes way down.

This is why Android devices have all that RAM.

iOS does not use this style of garbage collection and does not slow down in constrained memory environments.

So 1GB for iOS results in more performance than 3GB for Android.