I think hacker news aced it with the clean look, although sometimes I wish for a dark theme.
Other than that, I also think the tag density is higher than on Lobsters, where they seem to be using mostly one, or at most two, tags, whereas this website's front-page is using around three for each post.
Maybe the color scheme as well. And perhaps more negative space can be removed by making the column wider, like it is on HN.
The inconsistency makes it impossible for my eyes to settle into a reading pattern.
The choice of colors is also rather unconventional and not exactly appealing.
It's the old school magic of nested <table>'s.