It's like a good six reasons why this happened
Harrison Barnes not only not signing the extension the warriors gave him two years ago by stinking the last three games of the finals led to this. He signs the extension and the warriors are stuck with him
Okc not keeping harden after making the finals wih him Russ and kd. They keep just those three together and they likely are champions at least once by now
Chris Paul, Lebron James, and the players union refusing Adam silver's cap smoothing idea and instead allowing all that tv money to make the cap jump as high as it did allow d the warriors to have the money to give to Kevin Durant. If hey allowed for cap smoothing then the cap would gradually have went up unseasonably of giving every team like 20 million dollars in cap space.
Lebron James jumping from two different teams with an all star guard and all star forward within five years. Kevin Durant said openly Lebron paved the way for this decision.
Jerry west being a consultant for the warriors and telling Durant that if west was in his position he would have did the same hint. West winning one title and losing in 9 finals is a haunting career for an all time great athlete.
Oklahoma City getting younger and younger while kd got older was another. A team that once had Reggie Jackson, Jeff green, Kevin Durant, james harden, Russell Westbrook, serge ibaka, Steven Adams when kd was between the ages of 20-25 managed to lose every single talent unnamed except Russ and Adams was back breaking. Plus okc couldn't recruit for shyt. Kd was desperately trying to get pay gasol before gasol chose the bulls a few years ago over them and the writing was on the wall even then.