Actually...https://arxiv.org/pdf/1902.04738.pdf

On a more serious note, most c programs I see don't do very much of that, preferring to allocate fixed-size buffers on the stack. Additionally, most GC'd languages that aren't java have crappy GCs, and those GC'd languages that are java lack value types. This harms spatial locality quite a bit, and compaction can't fully compensate for that.

They are working on adding value types to the jvm, though; it will be very interesting to see how performance changes. (I expect not very much in practice—those projects for which performance was important were already using whatever tricks they needed to—but perhaps it will improve the ergonomics of performant java.)