[{quoted}](name=Stark of Wrath,realm=NA,application-id=3ErqAdtq,discussion-id=AANKRNr3,comment-id=00010000000000010000,timestamp=2018-04-24T17:25:11.971+0000)
She covers a lot of ground with her ult, and can sleep the champ before snapping back, and then skips away. That's pretty mobile.
Zoe's ult is not mobility. She covers zero ground; she cannot use it to open or close gaps, at which point she returns to her original spot. It's a glorified range increase, with the downside of putting her in very real danger (as it effectively roots her in the original location while allowing those closer to where she wants to hit to retaliate).
Zoe's sleep is also not mobility. I'm not sure what you're not grasping here, but CC =/= mobility. The ability to walk away from someone, after hitting them with hard CC, does not make a champion mobile. Otherwise Alistar would be the highest mobility champ in the entire game, given he has hard CC on 3 out of 4 abilities.