On the off chance that you're one of the minority of people who use the 3D Objects folder, you should know that as of Windows 10 release 1703, the 3d Objects folder will no longer be given special treatment by File Explorer.
Again, only a tiny minority of users actually make regular use of the 3d Viewer App that's built into Windows 10, so this change isn't going to impact very many people. However, if that's your go-to app when it comes to viewing and manipulating 3D objects, then be aware that it won't get a prominent place on File Explorer's sidebar when you open it. You'll have to either create a shortcut or click your way manually to the folder.
Initially, Microsoft's reason for including the folder in File Explorer's shortlist was that they envisioned millions of people downloading and manipulating 3D objects from the web. Not nearly that number of people do so, and the ones that do typically rely on some other, third-party program to view and manipulate their models. There are a number of excellent choices out there, and all of them are superior to the bare bones capabilities offered by the Windows App.
Basically, you could consider the Windows 3D Viewer App to be the 3D world's version of Paint. It will allow you to view and manipulate a 3D object in basic ways, but you'll quickly run into its limitations. If you work with 3D objects on a regular basis, you've probably already gained a good deal of familiarity with some other program that has more features on offer.
In any case, most people regard it as a generally good move. It's one less folder to clutter up the workspace, and the search phrase "How do I get rid of the 3D Objects folder in File Explorer" is one of the more commonly searched terms in the Windows Support database. Given that, Kudos to Microsoft for making this modest change. Sounds like they finally got the message.