alt Hacker Newseven for "downloads 2MB of JavaScript", it is often simply because the site is badly written (e.g. not careful about managing dependency), not necessarily because "JAVASCRIPT BAD".
Just look at the source code of amazon.com. It's a mess. But I bet it is more of an organizational problem than a tech stack problem, for a website worked on by literally hundreds of teams (if not more) where everyone crams their little feature in the website home page
> it is often simply because the site is badly written
I find that some techs tend to cause badly written code. I have junior coworkers that can write clear Python after a short intro, but can't write clean R after a year using it daily. I don't know if it is caused by the philosophy behind the language, the community, the tutorials and docs...