Java can be compiled to a native binary now, thanks to Java 9. No bytecode, interpreter, or JIT left in the resulting file. (Only available for Linux x86_64 right now).
Does the app use the most efficient methods provided by operating system? Is the graphical user interface consistent with the other applications on the same system? Is number of syscalls predictable?
That wouldn't make sense. Not only would it go against the Java philosophy of write-once-run-anywhere (Java is very hostile to cosying up to platform-specific frameworks), it would also be a mistake in practical terms - they're right to just keep maintaining JavaFX, which is a perfectly competent GUI framework.