I understand the philosophy and yes that has in a way future-proofed the JVM. The question is "Does it make sense to try and include advanced language features

I understand the philosophy and yes that has in a way future-proofed the JVM. The question is "Does it make sense to try and include advanced language features in a round-about manner into Java ?" Surely this approach only leads to additional complexity and broken features. Why not put that effort into a newer language running on the JVM ?