Not at all saying Ruby's compiler is more capable, more that typical Ruby code is easier to optimize by their JIT design than typical JS, largely because Ruby's

Not at all saying Ruby's compiler is more capable, more that typical Ruby code is easier to optimize by their JIT design than typical JS, largely because Ruby's type system is more sane. The whitepapers that inspired Ruby's JIT was first tested against a saner subset of JS, and shown to have some promising performance improvement. The better language/JIT compatibility is why the current Ruby JIT is actually showing performance improvements over the previous more traditionally designed JIT attempts. JS can get insanely fast when it's written like low level code that can take advantage of its much more advanced compiling abilities; like when it's used as a WASM target with machine generated code. But humans tend to not write JS that way. Agreed about Go as well, it tends to be on the slow side for compiled languages. I called it out not as an example of a fast language, but because it's typical performance is well known and approximately where the upper bound of how fast Ruby can get.