Why the Magic do this?

They will need to pick between Carter Jr or Bamba, and since Carter Jr was the main piece in the Vucevic trade, I think the choice is obvious. Adding Poeltl will be better insurance of keeping a good center rotation because Bamba might ask for more than he is worth. Also, getting Primo, a lottery pick this year, will help boost the Magic's wing depth, which is always a good thing.

Why the 76ers do this?

They finally ship Simmons for a great return. VanVleet is that main ball handler that the 76ers need and Anunoby will pick up the defensive load that Simmons will leave behind. Sure it does suck to lose Maxey, but they will still have a couple great guards on their rotation to the point that it won't even matter.

Why the Spurs do this?

They get their next big star in Simmons (even though I think Murray and Johnson can also be future all-stars themselves). If you hate to admit it or not, but Simmons is still a top 30 player in the NBA. He is elite at everything, but offense and that won't even matter with good offense players like Murray and Johnson. Plus adding Bamba, who can also potentially become the next top big in a new situation like San Antonio is just a bonus.

Why the Raptors do this?

With their current core, they won't have much success like they had in 2019 and 2020. Siakam can't be the best player on a championship team. So I think the best solution for them is to just rebuild because adding Maxey and Vassell who have enormous up-side to their already great young core will be a huge game changer in a couple of year. Also adding 6 firsts is just insane, especially since they are only losing VanVleet and Anunoby.