I said it the other day, 2016-2019 were formative years for the legacies and narratives of KD, Steph, LeBron, Harden, Kawhi, CP3. All of them either had or would go on to have historic-level teams at one point: '16 Warriors; '16 Thunder; '16 & '17 Cavs; 16 & '17 Spurs; '18 Rockets.
If KD doesn't join GSW, it becomes a crapshoot as far as who wins from '17-'19. The underscored issue with KD is that his injury history started in OKC when he broke his foot, and joining GSW's system probably preserved his remaining health compared to if he had stayed in OKC.