As of July 23rd, Android Oreo is sitting with a 12.1 percent share of the entire Android ecosystem. Breaking those numbers down further, 10.1 percent of users are running Android 8.0, while just 2 percent are running the most recent release: Android 8.1. Those numbers are relatively low for an operating system that was released 11 months ago, but it's par for the course for Android adoption.
Android Nougat has the largest portion of the pie with a 30.8 percent share, followed by Android Marshmallow with 23.5 percent. Next in line is Android Lollipop with 20.4 percent.
Google has introduced features like Project Treble within Android Oreo, which allows OEMs to update their devices to the latest version of Android without have to wait on qualification from hardware vendors.
"With a stable vendor interface providing access to the hardware-specific parts of Android, device makers can choose to deliver a new Android release to consumers by just updating the Android OS framework without any additional work required from the silicon manufacturers," wrote Google back in May 2017. However, it remains to be seen how many OEMs have actually embraced Project Treble given that the priority for most is to sell you the latest shiny new phone than to provide you with a free Android OS update.
On the other side of the pond, Apple wields complete power over OS updates and distribution, hence 81 percent of iOS devices are running iOS 11 -- the most current publicly released version. 14 percent of users are running iOS 10, while 5 percent are running an earlier version of iOS.