Quite often, we link in answers or comments to other questions, because a specific answer to that question seems helpful or presents another aspect. But we do not link to that specific answer, because there is technically no anchor of it. So someone following our link has to browse through all the answers, if we forgot to mention with our link (what happens quite often), whose specific answer we mentioned.
What's wrong with adding an anchor to answers? One could then link to them like in forum postings. Of course, it would be technically a bit more difficult, as forum postings don's raise by upvotes. But on the other side, it would be easier for users as they don't accidentally read the wrong answer.