Security (before deploying to AWS!!!)
Caching and cache-busting
Serving static content and gzip encoding it.
https://css-tricks.com/the-difference-between-minification-and-gzipping/
Gzipping reduces the file size about five times as much as minifying does. But, you get a little boost from minifying as well, and since it likely requires little additional effort in a build step, you might as well.
There is also some evidence that browsers can read and parse a minified file faster