Ruby, Python, JavaScript, Java and others also aren't "official Google", "Apple", "Microsoft" languages and they still run the whole web. It really question the brokenness of a company processes that refuses to use good tooling just because a corpo didn't tell them to.
Kotlin is full interoperable with Java APIs and libraries and at this point there's really very few cases where it's not a significantly better choice for Android development.
That's true for now. But there's nothing stopping Google from making changes to Android which break Kotlin support in ways we could never predict. From that standpoint, Java seems much less risky if you're building a large app that you expect to have to maintain and support for years to come.
> But there's nothing stopping Google from making changes to Android which break Kotlin support
It won't, that's what they addressed in this post by ditching jack and switching back to javac bytecode.
"Over time, we realized the cost of switching to Jack was too high for our community when we considered the annotation processors, bytecode analyzers and rewriters impacted."
