Yup, on desktop, the comment area takes up a 1/3rd of the screen and there is a lot of empty space on either side. Your reply is also too…tall? There is so much space around each action button and there are buttons at the top next to your name (permalink, collapse) and also at the bottom (up vote, down vote, reply) instead of having them all in one line. Also the vote count and post time are weirdly centered in the comment rather than on an edge to create clean borders. It makes no sense!
I’m on the website via a browser on PC. If the only way to make things disappear is upvote/downvote then that is another example of bad UX. I may not care about the post and now I have to proactively vote it up or down. On the flip side, if I was actually interested in a post and wanted to come back to that discussion later, you are saying it will now be gone from my feed. That stifles discussion.