Why they do this:

Lakers get a star guard in Kyrie who can help the Lakers be contenders next to Lebron and AD. They also get Markieff Morris who can space the floor.

Nets get a handful of good role players/young players. This gives them more depth and more talent for the future.

The Jazz get a big expiring contract and 2 firsts this means they will have a lot of money to spend in free agency and picks to help them in the future.

Wizards get the passing guard they need to lead their team and a couple seconds.