There are straightforward reasons — and some might be easy to fix.
It's so refreshing to read an article about balancing screen time instead of stating how bad it is and offering alternatives. My daughter is only 4 and she's spent the last year battling epilepsy and crippling anxiety. There was a point where she had this excessive movement issue and the only way we could get her calm and still was with the tablet. I felt so guilty with all the tablet time she was having, but for us, it's actually what allowed her brain to be able to heal. To prevent meltdowns from ending tablet time, I played a song as a warning that her time was about to end. Now we use a 60 minute sand timer for her to visualize how much time she has to play before she gets 20 min tablet time. Google family link has some great timers you can set to manage screen time with warnings before it turns off. This has been really helping us encourage independent play for an extremely needy child.