Oh no- that is often the misconception that most people equate to.
The volume of the text is not in proportion to its quality. This means that it the more words or paragraphs that you create on your post, the better the quality is. Sometimes, less is always more especially if you construct your paragraphs into straightforward and concise answers without any irrelevant information.
Additionally, there are lots of people who have made several posts that only contain 2-3 sentences but they were able to garner merits from it. At the end of the day, it is all about the quality of your replies and the construction of it on how it tells the message.
The misconception actually comes from what the OP has seen largely on the forum and I will tell the OP that most of the posts or threads he sees that they are actually Long post which I will say are mostly due to the signature requirements, most campaigns have quota of words or length that a post will meet before it is counted towards there paid post so these signature participants actually buttress their post to meet this criteria and mostly many People mistake it as to why they gain merit. But just as everyone said it bows down to the quality