I don't think that we're to the point of needing the functionality that collapsing comments provides yet (if we ever do, debatable as there are great points on both sides), but they way I use them is in this way: A poster makes a comment in a busy thread that I am very interested in seeing the first level replies to, and not the replies to those replies as much. So if Flagamuffin says something intriguing or controversial or whatever, I often want to see all of the replies to your comment. In busy threads, non-collapsing comments make it terribly difficult and hides a lot of that content effectively. On mobile, non collapsing comments make navigating comments almost obscenely difficult as well imho.Yes, but do you see my point -- with collapsibility, skipping past them (that is, ignoring the best content in favor of the worst) will be that much easier.