I don't think I have ever actually used the "back to top" link on a web page. Has anyone ever actually used one of those? I generally ignore them because I have a firmly placed habit of scrolling up when I want to go to the top, not looking around for a link.
I think these are a vestige of the old wild west web days when people called them "anchor tags" and tried to link up everything on their pages. And yes, I realize they are still technically "anchor tags", but nobody calls them that anymore. Even developers will call it a link while typing out the "<a href='…'></a>" anchor tag.