Let's say she enjoys several activities equally, yet access to one of them is restricted while access to the others isn't - she can do them as often as she wants. If her bedtime then is at 10, she is allotted one hour to enjoy the restricted activity, she hasn't used that hour today, and the clock strikes 9, why shouldn't she opt for the restricted activity?
Or is your actual goal that you want her to enjoy screen time less than she currently does?
I think there's a difference between 1) wanting your kid to do other things in addition to something that they already enjoy, and to 2) expect them to enjoy it less just because you don't understand why they find it enjoyable.
I also think this is a mistake parents should be more careful about making.
From what you've written it doesn't seem like a case of true addiction to me, but if it is, I apologize, and your concern is probably justified.