Whether children play enough isn't an obscure debate among developmental psychologists. If it's true that children who spend too little time playing struggle with executive function, then we may be raising a generation of kids with less self-control, shorter attention spans, and poorer memory skills.
See the link above for interesting research on the benefits and necessity of unstructured and imaginative play. I'm relieved to read it. One of my kids, as I write this, is making messenger bags for her dolls out of bubble back and duct tape. She was so busily engaged, I decided not to do any practise writing with her. (The bags are very nice ones too.)