To be honest they were introducing a new style of play which teams hadn't found out how to defend against yet. Once they did figure that out, his tiki taka style of play was never succesful again. Guardiola also isn't trying to replicate it elsewhere because he knows it has become ineffective.
Maybe in the media but the average football supporter was in denial and kidding themselves United90's/Arsenal early00's/Real's Galactico's/Chelsea under Mou etc were on par/better and would have had the beating of them if their era's collided.