Don’t need to read a complete reprint of the post above yours or part of a conversation flow. Worst cases are of the 10 paragraph diatribe followed by “ plus1” or “I agree” type thing.
Where they are cleaned up, it doesn’t usually happen in real time so it is obvious from the flow of the thread if the quote is necessary or the referred to poster. Where a reply is well out of context or possibly on another page, the quote box is often useful. Similarly where a portion of the quoted post is being used or possibly being dissected in stages for reply.