I leave it to the reader to decide whether the advantages are clear or not. For instance, in Kotlin you can perform operations on collection without converting

I leave it to the reader to decide whether the advantages are clear or not. For instance, in Kotlin you can perform operations on collection without converting them to a stream first, and collecting them with a certain collector afterwards. So in order to perform a single filtering operation on a collection, you need to do three steps in Java and just one in Kotlin. Another advantage is coroutines, which not only allow you to write asynchronous code in a common, synchronous manner, but also get rid of shared mutable state, since coroutines can send/receive shared state through channels.