I remember a lot of people saying "Now I don't need to learn Scala" after Java 8 came out.
Java 8 took a lot of the wind out of Scala's sails not by being better, but by showing enough improvement that the benefits of learning Scala looked less attractive than before.
Platform languages take slowly the best features of guest languages.
Additionally, type inference, value classes and pattern matching might not be at Kotlin, Scala, Clojure level, but they are good enough for most devs without having to deal with all the extra stuff.
