Fair point. The "with ease" part has also to do with Java's ecosystem. For instance, Martin Thompson used to teach people how to write a single-producer-multi-consumer queue. In a matter of hours, people can achieve 100M+ reads and writes on a 2014 MacBook Pro (I understand that throughput is different from latency, but given the fixed number of CPUs in this case, the latency of such implementation is also phenomenal). Better yet, Java folks have libraries like JCTools, so they don't event have to spend that few hours to get even higher performance.
My litmus test is how fast one can implement functionalities of the data structures/algorithms in the book The Art of Multiprocessor Programming in production quality. It looks chic languages like Rust are not there yet.
Don't forget "chic" languages like Rust have the whole C ecosystem at their disposal.
Having done Java for many years and recently also done Rust, I'm not very convinced one ecosystem is richer than the other, when we talk about high performance computing. I've already hit a few things that are present in Rust I wished to have in Java. Generally I find the multithreading/concurrency libraries available in Rust very good.
My litmus test is how fast one can implement functionalities of the data structures/algorithms in the book The Art of Multiprocessor Programming in production quality. It looks chic languages like Rust are not there yet.