The bucks need two things, a good young player to build around and their picks back in order to trade Giannis. The bucks get both their things with this trade. They could flip BI to get more picks. Herbert Jones broke out last season , but he isn't going to get better in a solid, toxic team. With the bucks starting their rebuild, it gives a strong chance for Herbert Jones to improve.
The pelicans become better with a big three of Dejounte Murray, Zion Williamson, and Giannis. The Pels have been secretly building a stockpile of picks, ready to make there next big move. The one flaw, is the lack of shooting, but tht shouldn't be to hard if they trade for Buddy Hield or Kevin Huerter.
Believe it or not Delon Wright has been playing in the NBA for a while. He's been a leader to many teams in the past; leadership and accountability had been the Nets biggest flaw ever since they moved to Brookly(Yes even the KD and Kyrie Era). Getting that type of player in the locker is key for young and growing players. Demar Derozan had Chris Bosh, Jokic had Danillo Gallenari, etc