“Abbey Road” is certainly one of their best.,,but it seems to lack that energy captured in their Trilogy set.
Geoff Emerick, their recording & mixing engineer, had departed during the White album so the team was falling apart.
That said, “Abbey Road” is far, far better than “Let it Be” - perhaps their worse thanks to Phil Spector’s production disaster.
I think it was Geoff, but one of their engineers did a terrific book about his time with the Beatles. Recounted how they came upon all those weird sounds. Said McCartney was a fiend at the boards, and was such a perfectionist that he’d be there long after everyone else left. Drove them crazy.