I am convinced, from 6 years, that android cannot do phone nor computer os, very well.
Android finally got alerts so, so (still no caller ID over Bluetooth headset, broken in earlier android version). Yet, reliable battery life marches backwards as phones glue in their batteries for earlier phone obsolescence. And phone alacrity is yet spotty even on a 3ghz octa core, where lagging makes phone use still sticky at times.
This is one thread with os short coming. At heart, the OS battle seems to be a battle for the use of one's own device by the device buyer-fighting against Google, the near sighted, unimaginative android device community, the cell providers, and dumber consumers that will take and allow any backward development if it is packaged as an upgrade.