He's certainly won pretty much everything going, but there is definitely a question as to whether they have done that legally and played by the rules to achieve that in the first place - obviously that has very little to do with Guardiola himself. Secondly, while I wholeheartedly agree that his style of football is extremely effective, I'd argue that it's probably had a negative effect on the game overall in the last ten years or so. His tactics win games and trophies, but I don't think his brand of football is particularly exciting to watch for the most part.
Also, the proliferation of teams trying to employ those ponderous possession based tactics means that football generally is more boring now - we saw it under Enzo, we won so many games, but were they that good to watch? You get a lot of managers it doing it badly as well - see Russell Martin. I think the widespread adoption of his style of football has taken a lot of the unpredictability out of football, flair players like we saw back in the late 90s / 00s are basically non-existent because unpredictable wingers and attacking midfielders don't fit 'the system'.