This. 2009 was a turning point in modern football, IMO, and the CL final was symbolic of that. On the one side you have Pep: A young coach obssessed with tactics to an almost manic level with a clear top down approach: He knew how he wanted to play, he had in mind what every player should do in every situation and instructed them painstakingly to do so. On the other hand SAF, a manager of the "old school" at that point. A great man manager, great motivator, a father figure to many players and probably one if not the best ever at building up a club but in his philosophy, he was rather opportunistic, adapting his system to his players and giving them much freedom. The outcome is well-known and Guardiola's attitude towards the game inspired many younger coaches to do the same. Not necessarily imitating his style, but the idea of concept football was born and teams began to have a much clearer identity. That's also when Klopp began to have huge success with his high pressing/fast transition style that he still applies at Liverpool. Those coaches simply leave less to chance than their predecessors. They train which runs to make, how to behave collectively when the opponent has the ball, force you to stay in your position when in possession and so forth. I'm not saying that earlier coaches never trained that stuff by the way. Of course they did but never to the same extent or even obsession. Modern coaches have a much more macro oriented approach than the generation before them. Thing is, the German, Spanish and to a lesser extent the Italian league understood this development far earlier than the EPL. Guardiola, Klopp and Conte were the first managers of that kind to work in England and slowly more and more clubs become open to it. That's also why I think that the EPL currently is stronger than it ever was.
And because I understand the worship SAF gets here I just want to make clear that this is no criticism or something like that. He's one of the best coaches in history but his time came to an end around that time. That's only natural and doesn't take anything away from his earlier achievements. That final simply marked the end of a cycle.