EDIT: The HN title changed so I don't know if this comment is relevant anymore. That sounds like saying "living is the leading cause of death". I mean, I don't particularly like JS, but it seems like we decided long ago that plain documents and links won't cut it. Everything, apparently, needs to be a rich web application with huge images and a gazillion of ads. Why is that Javascript's fault?
Also, JS is cached. First time will be slow, others, not so much The mainstream libraries are fast and optimizable (Angular/React/Vue/etc). Other, not so much.
This is a very weak argument.
* many 3rd party resources are not cacheable or may have bad policies
* caches may be more often cold then you expect. most apps still cache large combined blobs, which will invalidate with each release.
* pure JS size has still it's impact on performance
* caching won't magically cut all network roundtrips which you need due to architectural reasons