Reasons Warriors Do It: Commit to the long-term future of the franchise and to its young pieces. Get a haul of assets. Saves them a ton of cap space.
Reasons Pelicans Do It: There really is no need to explain here it's Steph Curry. Look at their projected lineup w/ him man. (Curry-Bledsoe-Ingram-Williamson-Adams
If you want more analysis let me know in the comments.