Minification in Hugo can be used for JS and CSS assets but you have to call it yourself in the templates. (refer to the Docs)
As for the rest of your comments (that are not related to Hugo), if you serve a lot of external assets each of these requires a request, same for images -that is why lazy loading is recommended for both scripts and images.
I suggest that you look into other channels for recommended ways to serve assets.
This forum is not meant for general web development.