Fair point, though I read it like this, which doesn't make the claim _so_ bold :)
> Twice as fast as other Javascript parsers (sic) written in JavaScript.
Yes, this was my interpretation too (should probably be made more clear). Most JS dev tools are written in JS (Webpack, Babel, VSCode) so there's a large use-case for a fast JS-native parser. It could also, theoretically, be run in-browser for a macro system or something.