Why do professors do this?

Is it just me, or does it appear like instructors are pressuring students to purchase textbooks through websites run by third parties, such as Cengage? These websites allow students to access textbooks, but they also come with homework assignments, thus in order to pass, they need to pay for the service.

query on proffs amazing but as one digest this,Professors aim for their students’ learning and development, which often involves challenging them with demanding assignments and exams that push them beyond their comfort zones. A challenging course can help prepare students for more rigorous academic work or real-world challenges.