Almost all websites are pretty minimal in terms of their features, but they're built as if they were an in-browser image editor.

Reddit is barely more than HN with pictures and a LOT of bloat inbetween. It could be as minimal as 4chan-style imageboards if you add voting and a slightly different comment view.

Youtube is just a tiled list of thumbnails or an embedded video player followed by a list of thumbnails. It could work 100% without JS outside of the video controls. Instead it's a huge, slow mess. It's also inconsistent; in my case it scales the list of videos from subscriptions to about 50% of the browser window's width, leaving a chunk of empty space on the sides. The startpage with basically the same layout always uses the full width.

A message board like HN is more difficult than you think to get right across a wide range of screen sizes, just because comments can nest many levels deep. HN arguably has problems of its own in that regard.