In my profession, we keep an eye on "study document" sites where cheating students pay to plagiarize prewritten solutions for homework. This homework is often l

In my profession, we keep an eye on "study document" sites where cheating students pay to plagiarize prewritten solutions for homework. This homework is often low-quality; it may score a "C" or lower when plagiarism is not caught. These are sites such as CourseHero, StuDocu, and StudyPool. Are these under the umbrella of "essay mills"? AIUI, essay mills are a different business (about to become obsolete by ChatGPT's intervention) where you pay a professional to write you an essay or thesis, including research and citations.