The 'by far' label is perhaps a bit of a stretch, but I don't think its proposterous opinion. Pep has still yet to prove himself in a team that isn't either readymade with generational talents, nor the excessive superpower within its league, nor one that has bottomless funds. Would he have been as successful managing Dortmund or Liverpool as Klopp had been? I doubt it.
Also more of a personal thing but I find his football boring as feck. He's lobotimised the game with his tiki taka nonsense, coaching the flair and excitement out of a player's natural game and turned the whole thing into a robotic spectacle.