Not many people are motivated to take optimization this far in the Java world.
On the .NET side, the language is more suitable because you can define your own value types (coming soon in Java AFAIK), and there is a lot of people using C# for game dev which is a big use case for GC optimization.
Unity has been integrating unmanaged allocators in their engine, which lets developers skip the GC much more easily (without having to manually preallocate and reuse memory, which isn’t anyone’s favorite workflow, and doesn’t save you much compared to a fast native allocator). I’ve also seen a couple of roughly equivalent projects, eg. Smmalloc-CSharp, github.com/alaisi/nalloc.
On the .NET side, the language is more suitable because you can define your own value types (coming soon in Java AFAIK), and there is a lot of people using C# for game dev which is a big use case for GC optimization.
Unity has been integrating unmanaged allocators in their engine, which lets developers skip the GC much more easily (without having to manually preallocate and reuse memory, which isn’t anyone’s favorite workflow, and doesn’t save you much compared to a fast native allocator). I’ve also seen a couple of roughly equivalent projects, eg. Smmalloc-CSharp, github.com/alaisi/nalloc.