He's too good to tank with, so the only option is to hold him out of games. There's absolutely no way that he's going to allow them to hold him out of games for 2 straight seasons of his prime when he has a chance at All-NBA. So, at that point, you're either playing yourself out of the race for the top 3, or you're trading your war chest for actual talent to build around SGA.
They came out of last year's draft with Poku and Theo Maledon. Poku may have potential but he just statistically had one of the worst seasons in NBA history. He's at least a year away from making any sort of contribution. Now they're picking 6th, outside of the range of immediate contributors. What he's tried to do since Westbrook was traded failed this year when he got the 6