you mean... like if people could vote on the best comments, and you could sort by the votes? The issue is that figuring out what is actually useful is intractable and subjective.
No, it’s a bit more complicated than that because the comments are threaded. It could take a few passing to find a gem comment. Also, the comments evolve over time meaning you might not find anything at the time of your browsing.
That's sort of how I feel about comment trees. ~100-200 comments is the safe max for me, after that, sufficient garbage is present to degrade readability. It's subreddit/topic/ToD dependent, since some are difficult to follow from the beginning.
I wish I could set multiple sortation options at the same time. So I might see the top 'best' post, followed by the top 'controversial' post, followed by the 'newest' post. Then the second best of each.. etc..
As for threaded, I like how StackOverflow handles this. You have separate top level answers, but underneath that is flat comments that can be filtered a tad for quality or totally unwrapped. That system works very well.