A Privacy Policy is Required by Third Party Services
Apart from governing laws, some websites like Apple, Amazon, and Google require website and app owners to post a Privacy Policy agreement if they use any of their services.
Many websites and apps use in-page/in-app advertising by third parties to generate revenue. As these ads also collect user data, third parties require the websites or apps to ask their users' permission for sharing their personal data.
For example, if you're using Google Analytics on your website, the Google Analytics Terms of Service requires that you post a Privacy Policy agreement. In addition to this, you must also disclose that you're using Google Analytics and some information about how it collects and processes data: