True, but it also removes the comments and the whitespace, leading to slightly better performance and memory usage. There are also less bytes to gzip on the server side.
Slightly, but is it enough to warrant the extra steps?
I don't think the difference is significant enough in this case.
That said, I do think there should be an alternative to minification+gzipping, like e.g. a compiled version of JS that is more optimized than a browser's own JIT compiler can do. Mind you, that might up being a larger package than the JS source code.
