The british blues rock thing was exploding in 68. Always thought that Macca, in typical Macca fashion, was just showing that he could do it too (as did Lennon with Yer Blues)
I like the sprawl of The White Album. An attempt to do Sgt Pepper II could have been dodgy. I remember reading that after Pepper people were asking "what will they do nex?." Someone said they heard a rumour they were going to set The Bible to music, or Lord Of The Rings. Good on them, that after releasing what was accclaimed even then as the greatest album ever, they release an unpretentious anything-goes no-fancy-cover take-it-or-leave- it album. Perfect for the place and time.