This is one of the new features of iOS14 and quite useful if you regularly use the App Library. New apps installed on the App Store will automatically migrate to the App Store, no more manually.
This feature is not already enabled, if you want, do the following:
Step 1: Open Settings> Home screen.
Step 2: You choose App Library only in Newly downloaded application.
Step 3: If you want to see notification badges for apps in the App Library, turn on the option In the Application Library right below.
From now on, when you download new apps they will show up in the folder Recently added of the App Library instead of on your home screen.
With adding folders Recently added Containing new applications installed on the device, we can see that Apple has learned the beauty of other operating systems (Windows, Android), though basic but still encouraging.