[The_rationalist]

What you're waiting for is already available with Kotlin coroutines (which has a very clean API btw) And no reactive streams still are useful for processing collection streams asynchronously and here again kotlin solve it all https://kotlinlang.org/docs/flow.html

[jacques_chester]

I like Kotlin coroutines and I've used them, but they (this argument is controversial) have a function colouring problem. As the JVM adds virtual threads I expect that a rebasing of Kotlin's coroutines will remove that objection.

Plus, sometimes, I want to use Java.

[ta988]

Also debugging with them can be quite painful. It is getting better, but I still pull my hair frequently.