I'm not speaking bad of Scala or the JVM: I actually agree. When the GC and overhead don't matter, a JVM language is an absolutely fantastic choice. I was more commenting that Rust can be simple if you architect it right, that's all.

I've mostly come to the conclusion that a mediocre engineer can write performant enough Java/Scala/Clojure/Kotlin/etc. Usually even more performant than what an inexperienced/mediocre C/C++/Rust engineer could write and have an easier time doing it. However trying to ilk out the last bit of performance in a JVM language can be very challenging.