Re: oh...
"...or the USB-A plug that fits quite comfortably into an Ethernet port"
I set my mother in law up with a USB stick backup regime once upon a time and she could not get it to work. I eventually visited her and decided best to watch her actually carry out the task (which works so often when a user reports a problem) and yep - USB stick in RJ45 hole each time.
She still finds it too tricky to do so does not bother - but that's a different issue.