One set of figures that I saw suggested that iOS 12.1 had a small lead over Android 8.1 in March 2019. (These were the most common versions at the time.) Cons

One set of figures that I saw suggested that iOS 12.1 had a small lead over Android 8.1 in March 2019. (These were the most common versions at the time.) Consider all of the versions of iOS 12 and Android Oreo, then Android had a major lead. That is before considering Nought and Pie, which I suspect is the range of releases that most developers would target.