The Steiners could probably handle rough use by any kid and come through it fine.
There is something to that ... Steiners are tough.
< In the background little Johnny starts breaking rocks by swinging the binoculars on their strap and Jane packs mud into the objective lens housing and proceeds to stir it with a stick.>
They would probably come through it still usable. But somewhat worse for wear. It certainly wouldn't do them any good. I'm not one to baby my equipment but I buy quality gear it generally shrugs off the unintentional abuse and lasts a lifetime with just light cosmetic damage to show its age.
But this is predicated on a baseline of reasonable use and common sense care. Neither of which children are known for.
If you catch your kid getting ready to use your Steiners to hammer nails you break down the door rushing out to stop them. If you saw your kid doing the same with their $15 Bushnells you plan on giving them a stern talk about taking care of equipment and you might pick up your video camera to get the shot. Hoping to send it off to a TV show or have a Youtube hit.