amraee i am pretty sure some app store analytics tools, could give you a number but that would the overall apps.
One thing for sure is that it's not any more the popular choice out there. I believe the decline started from 2016 and did reach to a substantially low figure by 2020. But thanks to Harman and distriqt and their dedication, AIR is now slowly picking up. I am pretty sure that the numbers have definitely increased from what it was in 2020. Even though we don't yet have a number that, we can brag about, AIR is definitely competing in the market with other 2d game development frameworks.