Minify/Compress JS file?

I see my js file already >700KB when compiling in production mode (in dev mode 2MB). I think it's still big, I'm wondering if I'm not doing it correctly because when I see the compiled app.js, it is not somewhat obfuscated or compressed, for example I see a variable name still stay as it is.

In my webpack.mix.js:

mix.js('resources/js/app.js', 'public/js')

and I ran npm run production.

I tried to use .extract() but it's just separating the file to vendor.js, the total size is more or less the same.

Is there anything else to do?