> I wouldn't have expected Java of all things to be run under binary translation
Why? The Java community has only just been working on ARM64 support at all over the last few years, and it's still a little limited, and macOS ARM64 support is only out a couple of weeks and only from non-Oracle third-party builders I believe.
You have to install a Java VM compiled for ARM such as the one made by Azul. If you just get the openjdk from the main website it is compiled for Intel and will be much slower.
> I wouldn't have expected Java of all things to be run under binary translation
Depends which version you have installed. It's a taken a while for the native versions to reach the mainstream channels, so unless you've specifically installed an M1 build you probably have an x86 build being run under translation.
Why? The Java community has only just been working on ARM64 support at all over the last few years, and it's still a little limited, and macOS ARM64 support is only out a couple of weeks and only from non-Oracle third-party builders I believe.