AIR support remains and there are always features being added. AIR as a cross platform platform for Win/Mac/iOS/Android is still alive and has quarterly releases. Any missing functionality can be added via extensions written in native code. I've open sourced a few for desktop including a webview. It uses Chromium Embedded Framework (via C#) on Windows and WKWeview on OSX (via Swift) https://github.com/tuarua/WebViewANE/

Others include FFmpeg, libtorrent,toast ports as well as porting of the C extension interface to C# and Swift.