I'd rephrase that as "Java usually isn't the first choice for perf critical workloads". It's still a very performant language if used correctly (outperforming C in some benchmarks where the JIT can shine), and used for lots of performance critical stuff.

Java is absolutely used for perf critical workloads, hell, I am fairly sure that there are no runtime in existence that would handle that load of memory pressure better - of course the problem is sort of self-made, not every allocation should have to be done in the first place in this case.

But Java is heavily used in high-frequency trading, is the backbone of many cloud infrastructures and it is such a large platform that there are plenty of small niches where it is used and performance is important.

True, though in any competitive shop it's still second to C++, as they can afford it.

Isn’t the niche where truly insane latencies are required absolutely dominated by ASICs and a general purpose CPU is way out of the picture?

I believe so