Actually the Lennon/McCartney songwriting credit was just a formality, something they never changed.
The vast majority of the Beatles songs were Paul songs, or John songs, not a collaboration in the least.
And George Harrison’s magnificent “All Things Must Pass” is by far the best solo effort in the post-Beatles era.
From what I’ve read, I think they were actually working together on plenty of songs up until the end of 1964 or so.
“All Things Must Pass” is by far the best solo...”
Agreed. George was my favorite - so I am biased.