It's not about need. I don't think Banchero is the best of the three (or four even with Ivey), but if I drafted Holmgren and my team will still have the worst offense, how am I gonna know if my team is improving? Hammond needed to come to the conclusion that Giannis only happens once in a lifetime, not once a year. By drafting someone who could very well be the best scorer on their core, that helps everyone else out.
If the issue is that you don't think Banchero will be that good, I can understand that part.