Like I said -- maybe, and, indeed coding-style fashions change. Something that wasn't important ten years ago may be important today. Java/Kotlin try to follow the mainstream, not break new ground. It's good to have such languages (I, personally, prefer them), just as it's good to have more adventurous ones. Java explicitly aims for a last-mover advantage, not a first-mover advantage. The goal is to learn 1, what works, and 2/ what's really important from other languages, and only then, maybe, adopt the most useful and important features.
I see the fact that Spring was immensely popular in Java for a while as demonstrating just the opposite: that overgeneralisation and second-system effect happen to everyone, even in a language whose design philosophy was oriented towards avoiding it. I see Java's adoption of generics and lambdas as acknowledgement that omitting those features didn't help encourage simpler code, it just made complex code even worse. I think it's the same for HKT and similar abstraction tools.