Grug like dense UI, but grug also remember what web look like before people who knew newspapers used it.

Newspapers look like they do for a reason. Grug eye tired sweeping too far left-right.

Grug split difference, leave room for user to use tiling window manager to make article take up half screen while other half is HN box to talk about article.

I think that is a good point, I also notice newspapers are not long and thin. And that is also for a reason.

Newspeper not long because newspaper printed on paper. Paper have limited height. Website not have limited height.

I mean, I have multiple paper rolls in my house that are multiple meters in length. I think you have some too. Paper can be made quite long, it's obviously possible. Ever heard of scrolls? The ergonomics are the reason, not the physical limits of paper.