Comment by lblume

> you have to assume

We don't have to assume. We know that JavaScript is slow in many cases, that shipping more bundles instead of less will decrease performance, and that with regard to the amount of content served generally less is more.

Whether this amount of baggage every web app seems to come with these days is seen as "necessary" or not is subjective, but I would tend to agree that many developers are ignorant of different methods or dislike the idea of deviating from the implied norms.