What about the gas guzzlers?

Sometimes it's about specs. If you have a 10 years old system that was top of the line (even mid-range might do the trick) back then you'll be fine today. If you have a more average/budget/third world setup, you may experience the bloat more strongly.
It also may have to do with expectations (for some people waiting a minute is an opportunity to go fetch water and for other an insult) or what specifically you browse. Social networks, for example, are big offenders. In my case the worst ones tends to be newspapers that won't let you see anything without tons of JS. One in particular would fire up the fans of my then-new-high-end laptop. It's cooler to run Unity than it is to read the news, not exaggerating. Some people choose to or are mandated to use heavy sites for work as well. For example, a friend of mine appreciates the functionality of Notion, while at my job it's the official documentation platform, and at a previous job it used to be Jira. I certainly don't appreciate the bloat/functionality ratio of Jira. Notion is heavy, but I haven't seen anything as flexible before, so I guess it's not _pointless_ JS, though I don't really use it as more than a markdown platform in practice.