Children who don't develop their imagination often become antisocial teenagers, who resort to destructive acts like smashing bus shelters and shop windows.
Now I see the light: Being bored is not only beneficial, but necessary—allows creativity to flow.
Some well-known writers say they used their boredom in a constructive way and wrote diaries or short stories. However, I could never settle on any one activity. I tried everything, did well, and moved on to something else. When I retired from full time work, I finally turned my hand to writing poetry. Then, I wrote songs, sang them into a recorder, and worked out how to jot the notes down on manuscript paper. Finally, after writing about a million poems and songs, I decided to write my life story. Having reached the very end of my exploration, I started writing a novel. At last, I've found an activity I'll never tire of. Learning to write properly, following the guide-lines of good writing, editing and sharing critiques with other members in the Internet Writer's Workshop fills my days. Each story leads to another. See my published novels at the bottom of the page
So—let your child become bored. Send them outside with no screen in their hand. They might yell and wail, but you can smile with the secret knowledge that it's for their own good.