Never say never, that's what I thought about Apple and objective-C, and they just invented a new language for it.
True, it runs in the same runtime, but it does allow them to slowly move away from 20 years of history. Mind you, the obj-C runtime / Foundation isn't badly set up at all, I'd argue it's better than the Java SDK.
Go and Java stdlib have very different opinions about the basic types, used by every app (like strings or maps, heck, even about concepts what is a class and class hierarchies, or how the stack is supposed to look like).
So unless you want to wage a perpetual war at the border between your app and Android base libraries, forget Go, or about any language that does not run on JVM.
Without providing close to 100% interoperability, replacing Java with another language would be insane. All the open-source third party libraries for Android (and there's plenty, and many of them have become the de facto industry standard), all of that goes out of the window. I don't see how it could pan out
If that is the level we are happy about you can already run with Kotlin today. Its not official Alphabet, but it is offical from the company that makes Android Studio and it is roughly to Java what Apples new language was to Objective-C.
Unfortunately that still means that there is no good way to write cross-platform mobile apps.
There is never a good way to write cross-platform apps. Cross-platform programs are always inferior to solutions specifically designed for a particular use case (e.g. touch input + mobile device, pen input + tablet device).
I agree there needs to be a platform specific input output layer, but assuming you are writing the same app on different devices there is always going to be a large core (essentially all the business logic, all models, all validation, all sync code) that is, or should be, the same on all platforms. It is that code I wanted to refer to.
