Yep. The concept of "screen time" conflates such disparate things as "reading a book on an iPad" and "playing Candy Crush."

In this instance, the medium is not the message. Books, movies, etc. don't suddenly become more addictive just because they're on glowing rectangles. The glowing rectangles enable additional, potentially-addictive experiences that weren't possible without them—but you as a parent have complete ability to disable these experiences. A glowing rectangle that can "only" function as a library, encyclopedia, movie theatre, radio, and (if you like) chatroom, is still a useful possession, but likely not an addictive one.