Windows 10 has the concept of multiple desktops. This is an extremely useful feature, but I suspect that most people use multiple desktops in only one of a few ways. For most people, multiple desktops serve as an organizing method at a relatively coarse grained level. They probably have a desktop they use for work, and another desktop for something like media, play, or Internet type things such as mail and instant messaging.
This is a perfectly legitimate way to organize your desktops. When you organize in this way, you would still be organizing your windows in the traditional way. At first blush, most people probably think of multiple desktops and window management as separate concepts. However, Windows 10 also has the concept of tiling, which they call snapping, for managing windows on a single desktop. When used together with multiple desktops, snapping can be a powerful way to manage your workflows.
One of the common problems with snapping is that if you have multiple windows on a single desktop and only two of them snapped, then going to any other window that may cover both of those snapped windows means that you have to reactivate both of the snapped windows in order to get back to your nice snapped view. If you instead put that snapped view onto a separate desktop, then when you select any of the snapped windows, you will automatically be taken to that new desktop and it will contain only the snapped view, which is what you wanted in the first place. This saves you time by not forcing you to select each of the snapped windows.
I don't find it particularly helpful to think of multiple desktops as topical organization. I find it more useful to think of using multiple desktops as a means of optimizing your workflow for selecting certain applications over others or for selecting groups of applications as a whole that you may want to use in conjunction with one another.