Why each team does it

Warriors They get rid of 2 bad contracts of underperforming players together with 3 seconds, for movable players who can help their rotation, they get two bigger guys, two bucket getters and another wing defender, even if they all dont workout the Warriors can easily package them in future trades.

Mavericks They take a swing on a bad contract together with a second similar with what happened to Kristaps Porzingis but this time they get a 2nd and the underperforming player.

Spurs CP3 might be getting old, but hes still Chris Paul he can help mentor the young players on the team and potentially make Wembys game easier paul is a great playmaker and they get him and his contract for a couple of older role players together with 3 seconds.