Adoption of ARKit isn’t great as less than 1,000 apps of the 3M+ apps in the App Store have not installed it since its September launch.
Installs have been trending down. October installs were down 32% from September installs and November installs were down 26% from October installs. While it has only been a week, December installs were actually 10.5% higher than November but still 18% lower than October.