Uhm, what. They're basically overhauling the entirety of Android all the time: New JIT runtime with M, dismantled old mediaserver framework for security reasons

Uhm, what. They're basically overhauling the entirety of Android all the time: New JIT runtime with M, dismantled old mediaserver framework for security reasons, fixed the notification mess by adding channels, permissions were finally fixed in M, every release is seeing improvements to battery efficiency.