My personal user style for old.reddit.com extends the comment width to the whole screen and moves the horizontal action list for each comment to align with the username and the right side of the screen, while changing the font to one I find easier to read as well as bumping the font size and line-spacing, as well as generally adding some small amounts of space and colour here and there to help separate elements.
It's evolved over a few years now and the combination of changes means that I don't generally lose much in the way of content density in the general case of a post with mostly small to medium comments where the increased body text size is balanced with the removal of the space for the action bar. And it was even better before I got a bit older and decided that I should bump the font size up another pixel to make things easier on my eyes :)