You can't take the same approach on iOS but to Apple's credit, they do a great job with user privacy with their Screen Time permission. Apps with that permission get the ability to restrict other apps on the phone without ever knowing what they are. They can even report data back to the user without ever knowing that data.
Source: I am a developer of Clearspace, which is an iOS Screen Time App https://apps.apple.com/us/app/clearspace-reduce-screen-time/...