AFAIR, there are also some 3D graphics libraries for Kotlin Multiplatform.

I have the hardest time figuring out whether I should use Kotlin, Dart/Flutter, or React for building an iOS and Android app. I don't care about the GUI part, but I want easy access to all APIs (like Health Kit, Health Connect, sensors) and relatively stress-free development. When I was learning Flutter a few years ago, it was very frustrating because its documentation and username were scant and scarce. Is it better nowadays?