Why is initial webpack dev bundle so huge in JHipster?

I've created a new JHipster monolithic web application with Angular as a client-side framework.

After running npm start I've noticed that the file 'main.bundle.js' is around 16.6 MB.

I am aware that this bundle is supposed to be larger in development mode but I would like to reduce it as much as possible.

Are there any ways for achieving this?