MacRumors:
Apple has posted the first stats for iOS 13 adoption since its launch on September 19th for iPhone.
Apple shared the statistics on the App Store Developers page which was updated today. Apple reports that iOS 13 is installed on 55% of all iPhones introduced in the past four years, and 50% of all iPhone devices, as measured by App Store activity.
This year, Apple has broken down the stats between both iOS 13 and iPadOS which were launched at different times this year.
Adoption rates are pretty much on par with iOS 12 at the same point in its release.