An interesting point.

I think it would be better to merge ASTs rather than text files that represent code. The annoying issues with merges are all about the text representation. When there's actually different logic changes in two different directions the merges cease to be annoying and start to require domain knowledge.

Of course getting from this hand-wavey thought to working software is difficult. Perhaps we first need to start focusing more on the tree nature of code even in the editing tools?