The desktop button actually dates back to Windows 7, but is handy nontheless. On the bottom-right corner of the desktop is a secret button. Don't see it? Look all the way to the bottom and right, beyond the date and time. There you'll find a small little sliver of an invisible button. Click it to minimize all your open windows.
There's also the option to have windows minimize when you hover over this button versus clicking. Select your preference in Settings > Personalization > Taskbar > Use peek to preview the desktop.