Earlier quoted context omitted.
Disabling JS is incredibly beneficial for browser performance, battery life, privacy/tracking protection. As an added bonus, it protects you from malware from all the vulnerabilities in Javascript engines.
It also makes a lot of basic features on websites unusable. Just an HN vote uses JS. They deliberately added a fallback to work without it too, which most websites won't do, but it still has to reload the page.
There are some annoying websites that can't manage to display simple text or even a basic image without JS (which is just bad web designers doing bad web design) and some instances where the content I need is obscured by something that doesn't behave without JS (like an expanding menu spewed out all over the place because JS isn't there to hide what hasn't been selected/hovered over) but in those cases it's usually just 2 clicks to solve the issue (either for just that visit or for every visit to that domain in the future as well) so it's not really a big deal. I'm currently using HN without JS and it's great.