There are lots of reasons it could be, or could not be this. It could be related but not directly, like a lack of sunlight. That could be as a result of screen time instead of sunlight, but that’s not necessarily screen time’s fault—anything could keep you from going outside. The evidence that screens in particular are causing these problems is lacking. Same with social media, though I’d be more open to believing that.
There are lots of reasons it could be, or could not be this. It could be related but not directly, like a lack of sunlight. That could be as a result of screen time instead of sunlight, but that’s not necessarily screen time’s fault—anything could keep you from going outside. The evidence that screens in particular are causing these problems is lacking. Same with social media, though I’d be more open to believing that.