If they'd stayed together, then their solo stuff would be considered Beatles songs. And people would be analyzing them and asking who wrote what or who was responsible for different parts of them.
So, I think this would have been a strange phenomenon that no one would have considered if they had stayed together. Maybe this gives us a true clue as to what post Abbey Road albums would have sounded like. It would have been albums consisting of the Beatles otherwise solo stuff. Some lyrics would have changed, I think. Consider "Band on the Run." With no Band on the Run, Paul would have written the tune but with a different title and lyrical content.
Maybe some of George's lyrics would have been changed, too, ex. Wah-Wah. Or even "I Me Mine."
The most remarkable part that we can't account for would be songs truly composed in collaboration with each other. Those might have been unique and stand apart in their own right apart from their solo stuff. In other words, these would have been Beatles songs that have never existed in any form in their solo outputs. When I ponder this, I wonder about what could have been and never will be. I think we missed out on some gems.
