My best effort to satisfy the big issues of the moment, in order ... 1) Durant wants to be undisputed #1 on a contender 2) Lakers want Kyrie, need more not-has-beens 3) Nets want the best they can get 4) Spurs want to use their cap space to gain assets
Raptors/Durant - in sacrificing their best youth (and OG wants out anyways), they get Durant plus two more quality veterans that fit very well with FVV and Siakam, while keeping veteran bench players.
Lakers/Irving - once they get over the fact that they must give up two distant-future firsts to get what they want, they end up with Kyrie plus two of the best veteran shooters in the league - with one of them a forward.
Nets - Ben Simmons is often overlooked, but this trade is about him. The trade is full of good young players who can easily play off a great facilitator, and they all have plenty of time to grow with him. The Nets give up a first because the trade gives them the full $37mil trade exception for Kyrie, which can easily be converted into even more picks.
Spurs - get to use that $40mil of cap space for good picks in the distant future, plus offer two of their solid veterans for another late-first next summer.