Minifying is not as good as it could be?

[Giveback007]

The application I am building will be size sensitive so the extra kB is relevant as this result may add up across different packages.

After minification, popular package "lit-html" came out to around 16KB (11.33KB gzip) even though it is touted to come out to 3.7KB minified+ gzipped:
https://bundlephobia.com/result?p=lit-html@1.3.0

Would love to know if I am doing something wrong, if so how may I fix this?

["@snowpack/plugin-optimize", {
        minifyJS: true,
        minifyCSS: true,
        minifyHTML: true,
        preloadModules: true,
        preloadCSS: true,
        target: 'es2015'
}]