Are you implying then that the Closure Compiler mitigates or even eliminates the need to carefully examine the output sizes because of its optimization capabilities? If so, that's great, but I do remain skeptical about this, based partly on my experience described above. I don't mean this in a sarcastic or dismissive way but I was expecting to see something along the lines of:

console.log("Hello world!")

I realize this is a silly example for such a powerful tool but I just wanted to quickly get a feel for what the compiler is capable of before I committed a whole lot of time to learning the language. All I got out of the exercise was that the compiler creates a much larger minimum package size than I'd hoped. I'd appreciate any suggestions on a better way of proving its value for the cautiously curious. The language itself seems great, as does the community.

Perhaps it's just a different paradigm from npm/webpack, e.g. utilizing a rich built-in library rather than, yeah, carefully grocery-shopping for only the components you need? I'm not saying one is necessarily better than the other but it does intuitively seem that choosy shopping will tend to yield a smaller package size, at least for small-to-medium applications.