Wayyyy back in the day, people thought they could make smooth scrolling "better," e.g. nicer easing, more responsive, etc. There is, however, no actual benefit to this, no.
In this case it's crazy choppy for me. My firefox updates my scroll position on this page at like 10FPS on a recent ultrabook. So definitely not a success story for "better smooth scrolling".
If I had a lot of legal text that I wanted people to scroll by then this would be a good dark pattern.
That's at least one use-case I hadn't thought of haha.
I wonder if there are any legitimate non-dark pattern use-cases.