The Nets need to shake things up, because as of now they are a bad team without their own draft picks with players who are too old to rebuild. So here they move Bridges and DFS, two very good 2-way wings for a haul centered around draft picks. They pick up the number 8 pick in this draft, in addition to a number of future Orlando picks and a young point guard in Anthony.
Orlando needs shooting around Wagner and Banchero. If your two stars both shoot poorly from 3, you need high level shooters around them. Bridges gives you that, plus some shot creation, very good defense when he is not having to be the number one option, and experience in playing off of high usage guys. They move a lot of draft assets but it is worth it for them to get a guy who slots in perfectly at the 2, helps them maintain their defensive identity, and will open their offense up more.
Cleveland gets in on this to reshuffle their backcourt around Mitchell. They add another pick in the draft, get another future asset, and also add two wings in DFS, who can fit in to help fill their hole in perimeter defense (I also think his 3pt percentage will return back into the upper 30s playing with a guy like Mitchell) and Keldon Johnson, a guy who can score well and has shown flashes of two way ability who may need a change of scenery.
The Spurs get a real point guard who can run their offense, and really help unlock Wemby. Garland is also very young so he fits into their timeline well.