Well, it is much more difficult to write a paper nowadays with the ability of professor's to detect unoriginal content. In my day,(the 1980's) you cold get away with paraphrasing passages. Most Universities consider paraphrasing to be plagiarism. That is the "official" line coming out of Ivy League schools such as Harvard.
While it is better to read your source, close the book and write from memory, using your own ability to use the knowledge you have gained to write original sentences, it can be very difficult for many students to do. This is due largely to poor reading comprehension levels which has a component of a lack short term memory.
Other students are ESL (English as a Second Language) and I do feel for them. It is difficult for many to even write a rough draft that makes sense. This is where editing services come in handy. If a student can express enough of an idea, concept, or theory, a good editor can wordsmith the draft and come out with a good paper.
This begs the question, "But how will a poor writer learn to write?"
That is a good question. Though through practice one can improve his writing ability, by the time one reaches college age, it is do or die time. Colleges and Universities expect their students, whether ESL or not, to write coherently.
This puts the student in a quandary. He must now decide if he really wants to learn to write or does he just want to get a degree. There are plenty of people out there who will write papers for a price. There are also legitimate editors who can do deep editing. Providing original content can be tricky so the demand for paper writers seems to be quite strong. It is a thin line between heavy editing and writing the paper for the student. Many students prefer to have the paper written for them, from scratch. Other students would never dream of letting someone else write their paper. I belonged in the latter category. It never even occurred to me in college to have someone else write my paper. This was due to my confidence in my own writing ability. I am fortunate that writing comes easy for me. But, for those form whom it does not, I do feel for them. Coherent writing is a necessary skill in most any white collar job.