It’s not “amazingly non-performant” though. I assume the comment was thinking of something dynamic being run through an interpreter, which might be 1-10% as per

It’s not “amazingly non-performant” though. I assume the comment was thinking of something dynamic being run through an interpreter, which might be 1-10% as performant as native, but if you design the bytecode to be statically compilable and simple you can do a lot better. A 30%ish performance hit really isn’t bad for perfect cross-platform compatibility, determinism, and sandboxing for free, and the gap will close as it matures