That strategy always falls apart when the ecosystem goes into a direction that the guest languages did not forsaw, or already created incompatible concepts, and then get the dilema of what to expose from the underlying ecosystem.

Using Kotlin as example, its initial selling point was Java compatibility, now it wants to be everywhere, and its Java compatibility story is also constrained for what Android Java is capable of.

So the tooling attrition increases, with KMM, wrapping FFI stuff to be called from Java like coroutines, and everything that is coming with Loom, Panama and Valhala.