TechSpot published a guide about removing "3D Objects" and other shortcuts from Windows 10's file explorer A quote from the article:

Most recently Windows 10 introduced a default "3D Objects" File Explorer shortcut which takes up space if unused. In this article we'll cover how to remove that somewhat annoying shortcut on Windows 10, and along the way see how to remove other such shortcuts (Music, Videos, others), so you can tweak and personalize as you want.

 Remove "3D Objects" and Other Shortcuts From Windows 10's File Explorer