I realized the multiple parents thing was a total red herring. It really is just the immutability. What I was thinking of was having multiple parents over time

I realized the multiple parents thing was a total red herring. It really is just the immutability. What I was thinking of was having multiple parents over time rather than at the same time like a merge commit. But that would just be one (not immutable) parent but with a history of what that parent was over time, not "multiple parents".