Thanks, Stephen.

Your link went to the G7X. I do have a G7X Mark II (apologies for the confusion). That video is here. I'd watched that video several times and my experience matched it until 4:58, at which point my PC did not make the "connection noise," didn't ask what I wanted to do when the device connected, and the camera continued to display "Connecting" as shown at 4:32 (until it timed out).

HOWEVER, on a whim I ran the Windows 10 Troubleshoot program and chose Hardware and Devices. It reported a problem with the Canon driver, did some magic, prompted me to reboot, and voila! The next time I went through the steps it worked!

Thanks for your, and others, assistance! Although those suggestions weren't the solution, they kept me hunting until I (er, the Troubleshoot program) discovered the faulty driver. And FWIW, I had removed the device from the Devices and Printers dialog a dozen times (although it was still displayed in that dialog after removing it--a sign of trouble I expect) and checked to make sure it wasn't in the Device Manager (it wasn't). In any case, I'm up an running.

Happy Camper