same here. i use it as a kind of mental bookmark as i move down the page because I know that its very, very likely i'll get distracted by somethingand have to temporarily leave the article.
however, this is probably a habit for a minority of users because it only makes sense on desktop. if you're reading on a mobile touchscreen-device this highlight-as-you-go tic just doesn't make sense
I'll do it on my phone, but it's usually just over the area I was reading when I decided to look away, so it's not while I'm reading, only if I'm going to go somewhere else first.
however, this is probably a habit for a minority of users because it only makes sense on desktop. if you're reading on a mobile touchscreen-device this highlight-as-you-go tic just doesn't make sense