... a championship because of that pick. Which pretty much limits the definition of a "successful tank" to the Cavs (Irving) and the Spurs 2x (Robinson, Duncan), and then probably a few more examples from 40+ years ago (I think the Lakers and Rockets with Magic and Olajuwon, but I admit I don't know how the lottery/tanking worked, or if those teams did it at all).
I consider a successful tank as losing on purpose and then getting a franchise star. But I also consider a successful tank as getting the role players or favorable contract situation that enables you to then sign a franchise star to succeed surrounded by a strong cast that was obtained through tanking. And even without winning a championship, if you are a contender for a multi-year window because of intentional losing, then it's a successful tank, IMO. And I think a lot more teams fit that definition, though I admit it's a more complicated question when you expand the definition.