I figured this out on my own, finally.
The answer is: clicking on the page numbers on the lower left corner of the open document window will open a sidebar with thumbnails of the pages, with numbering at the bottom. So that slider bar can be dragged until the appropriate thumbnail is visible,
click on that page, and voila! You've accomplished in three clicks what you used to be able to do in one!
That sidebar is also available via the drop down menu View-->Sidebar-->Thumbnail.
Macs still have the drop down menu, dunno how it would be done on a Windows machine if clicking on the "page x of x" in the bottom window border doesn't work. Haven't been able to discern how/if the sidebar can be accessed via the "ribbons," and Word in-app
Help is wholly unresponsive.
BUT! If you want to know what page number you are on while scrolling/dragging the slider through a long word document in Mac Word 2016, just click on the page numbers, or View-->Sidebar-->Thumbnail. Lost functionality returned!