The revised conventional wisdom among critics and hipsters is that Revolver is better because it was more groundbreaking and experimental and Sgt. Pepper was just reinventing the wheel, and only touted as an era-defining masterpiece because of massive hype and better marketing. I don't entirely agree. Pepper refined the innovations of Revolver and applied them to something that was more immediately enjoyable and friendly (I mean the first track literally invites you to "enjoy the show"). It was an ambitious musical statement but also one that was accessible and entertaining to a mass audience, the best of both worlds. It was pop-art in the purest sense of the term. It's not hard to imagine how that would resonate with large swaths of fans and average listeners in 1967 in a way that Revolver didn't the year before. It didn't become a cultural event just because it was highly anticipated and smartly promoted, it's also because it was just fucking good and exciting and fun as hell, and still retains some of that even today.