The Wizards are likely going to select the best player available. That player, in this particular case, is LaMelo Ball. John Wall has been injured the past few seasons, and while the Wizards have not been particularly good, it should be noted that Wall also carries a nearly-50-million-dollar contract. Selecting Ball does not necessarily mean they trade Wall (or that they would even be able to), but it would absolutely give them flexibility.
LaMelo Ball has one of the highest floors in this draft class. He would make an instant impact for any team he’s drafted to. Ball has the court awareness and passing ability to become one of the best point guards in the NBA. That trait alone almost ensures he will not be a complete bust at the next level. That said, he needs to improve his defense and has to take better shots. I do trust that both of those things will come to fruition, though.
Ball could fit on the court with both Wall and Beal, too (especially if his shot becomes consistent). Defensively is where the issues come in. He would likely start his career as the sixth man if the Wizards select him, but again, I would watch for a John Wall trade.