Those teams stayed together. That's a bit different. When you're the best and the vast majority return and you remain the best, its not that surprising.
Look at the number of stars who have won titles for multiple franchises though. That list is pretty small. Typically once the star moves on, his days of winning championships are over. There's exceptions to that, an extremely motivated Shaq proving he could win without Kobe in Miami. LeBron is a real oddity but he's arguably the GOAT. Kawhi won in Toronto but timing and luck was in their favor for that run. I can't think of any others right now.
Durant hasn't led a team to a title until he joined a team that had already won a championship without him, and won another since he left. He's not who he was at his peak either anymore at 34 year olds and suffering the injuries he has. That's not to say he can't contribute to a team with championship aspirations but I believe the days of being the best player on that team are. He's not leading us to a title. If we want to win then Booker needs to take that step that Wade did when Shaq arrived in Miami into becoming a superstar. He's going to have to lead this team. I think part of why we fell short is even though he surpassed Paul on the court he still led him lead and looked to him as a leader. He can't do that again with KD. He needs to step up, as he's shown he's capable of doing, and take over when everything's on the line or this team will short.