If you want the actual reason, this is called reengagement, and its purpose is to get users to use the app again, meaning more ad revenue. Subscription apps don’t do this because they want the user to forget about the app so they get paid while providing no service. But ad driven apps only get paid when you see an ad on the app, so they’ll send these reengagement notifications. Social media apps will use something like “This post picked for you”, or “This many people viewed your profile”. Same thing.