Originally, the text had one non-ASCII character, an upside-down exclamation point. A series of unfortunate (but typical) things happened to that character, turning it into 9 characters of nonsense, the 9th of which is also an upside-down exclamation point.

It looks like ftfy is just removing the first 8 characters, but it's reversing a sequence of very specific things that happened to the text (which just happens to be equivalent to removing the first 8 characters).