The real problem is that designing for different screen sizes, especially with responsive design, is very difficult. For my personal projects, screen size is the factor used to determine layout. Mobile/tablet/laptop/desktop is irrelevant. My goal with smaller viewports is to make the layout as similar as possible, without the user having to scroll horizontally. Because I don't want to change the layout too much, I do…
The real real problem is that so many sites overcomplicate their design. HN works beautifully on any window / screen size.
There is no way to format your text, even stuff that's available since MS Word 1.0, such as bold or italic. Even science papers have formatting so I don't buy the "overuse of styles" BS.
There is no way to have avatars or some other ways to distinguish users (or mods!) to make this place feel more like a community in real life. I've gotten used to it but it still sucks.
The contrast is super low.
HN is an MVP for a super minimalist forum that wouldn't fly for any other kind of community except for the intersection between hackers and wannabe entrepreneurs.