Even away from the Android world kotlin is gaining significant adoption. The enterprise space is very slow to change anything, hence everyone's still on Java 8. Google's endorsement of Kotlin is worth a lot. Just like "no one ever got fired for buying IBM!” Even if your enterprise has requirements nothing like Google's :)
At my day job, we ported our enterprise workflow product to Kotlin. We did it gradually, a package at a time as that package had enchaments made to it. There's virtually no java in the codebase now.
The developer productivity is a lot higher than java 8. Ultimately less key strokes to achieve the same thing. Lots of the recent Java enchaments are a step in the right direction but probably too little too late.
Kotlin + IntelliJ are one of the few IT tools that are actually a pleasure to use. I really can't recommend them enough!