Now if making paragraphs is a good writing practice, then determining what length should a paragraph have is crucial as well. I do not support the idea of writing lengthy blocks of text by any means. So, it applies to a paragraph's length as well.
i.e., you must not only aim to write in paragraphs but also in short paragraphs. By short, I mean not more than 3 to 4 lines and 100 to 150 words.
Writing lengthy paragraphs kills the entire essence of making paragraphs. It brings nearly all the disadvantages of not making paragraphs at all.
Short paras, give a precise and compact look to your content. It makes it easier to read. Short paragraphs work tremendously well especially if you need to explain a difficult concept. Short paragraphs helps a writer win over a reader's mind psychologically.