Filling up a streaming services with "whatever" is necessary, especially when you stream in hundreds of countries and your viewers have different age, taste, preferences, ethnicity, religion, gender, and background in general. Offering something for every taste is crucial if Apple TV+ wants to expand and become popular. For example, there are people who enjoy documentary films about history more than anything else, or people who enjoy horror or Sci-Fi movies and ignore any drama. Imagine if the apps on the App Store are only those specifically picked by Apple as worthy to be on the App Store. At the end, offering an extensive catalogue, including local productions like Netflix is what makes people want to subscribe and maintain their subscription, not just a few good movies that you can watch in a single weekend and then unsubscribe.