It is a high bar, but consider what happens when you get an inconstant merge. With text representing a program you get a compiler or interpreter error and can

It is a high bar, but consider what happens when you get an inconstant merge. With text representing a program you get a compiler or interpreter error and can view and edit the text to fix things up. With something like a CAD drawing you may not be able to open the file, or it might be almost incomprehensible to the user (if you broke coordinate transforms or accidentally combined sub assemblies or something). If you are really unlucky you end up with something that looks okay but subtly breaks the application in a way you will not notice for a long time, and then it’s going to be hard to fix. Oh, and you need to implement this for every file type.