Because people like to play games, take photographs (the camera on your J7 while probably adequate pales in significance to top end phones) and other high proce

Because people like to play games, take photographs (the camera on your J7 while probably adequate pales in significance to top end phones) and other high processing tasks that your budget phone simply can't do and that is often inconvenient to pull out a laptop for. Such as photos, or gaming on public transport.