Since Android was first adopted and modified by OEMs, Google has had a problem with keeping the end user experience consistent and up to date. This is part of

Since Android was first adopted and modified by OEMs, Google has had a problem with keeping the end user experience consistent and up to date. This is part of their solution at the app developer level, and has evolves from previous SDK layers that provided compatibility for older OS versions. At the OS level, Android has been modularized to take parts of the OS out of OEMs' hands to enable Google to add and update features with OEMs' intervention. OEMs can still opt out from all of this and do as they please with the Android Open Source Project (AOSP). Amazon isn't constrained by Google for their Fire OS, for example, other than by competitive imperatives. It is aimed more at Samsung and other OEMs who have modified Android to make their products distinctive in some ways that make life difficult for Google when Google wants to propagate new Android features into the installed base. Partly due to their own early decisions (that are difficult to second guess) Google has always had a much more difficult time making Android a consistent end user experience than Apple. It has harmed Android adoption. Google has put in a lot of effort, more or less effectively, in multiple dimensions, to fix that.