Yes, I was wondering what the hell they did to my "back" button. Then I saw that I had "visited" the page something like 8 or 10 times just by clicking the article link here. How the hell does that work? And why?
It was designed to accommodate highly JS-driven sites/apps, where user rarely, if ever, clicks on regular <a href="">, but notion of "going back" is still a thing.
Of course, this API also opened floodgates to all sorts of scammers.