[JohnKacz]

I saw someone recently post the idea that Java/Scala/F# almost functioned as LTS/Stable/Dev in reference to how these languages were sharing impact.

[ragnese]

I think the person actually said Java/C#/F#.

But in any case, I'm thinking that the real timeline is more that Java is prioritizing features that are most attractive from Kotlin, which borrowed the ideas from Scala. But Scala never got super popular, so there was not much pressure or "proof" that these were good ideas until everyone fell in love with Kotlin.