There IS an exception. If the thing they choose to do with their time has online instructions or they will be learning from a tutorial, etc, then the screen can be used to a degree.
They start off bored. They may get ahead on some homework. The littlest one takes the longest to figure out what to do. Often times I ask if they want to play a board game, or go somewhere with me, walk the dog, etc. But if I'm in the middle of something else, it's up to them.
It takes a few minutes, but, before you know it, they're on the floor in their bedroom drawing, or building something elaborate out of cardboard, the LEGOs come out, or nerf darts start flying through the house.
And for the older kids, they will get out of the house, reach out to a friend, read a book, or study a new topic.
Being bored doesn't last long when you don't have a choice. The hardest part is getting started with that "something new".