Question! Performance on Web

Hello,
I know my ignorance about arquitetury, but i want to understand web compilation perfom for that project.
Here we programing in JS for that, and the code compile to native C/C++, for then compile to JS WASM?

How much perfom is using this project for Web instead of GdScript.
I foudn that project on https://github.com/cart/godot3-bunnymark, they list many other languages for godot, but i know that the numbers they found is for native test. I think, if all they have test on web it's gonna have almost same perform.

So, have some optimization in this project, for the web builds?