I could be wrong but I believe the Blueprint assets are stored in a binary representation. So that rules out vanilla tools like patch/diff for the most part.
See the sibling poster, they did actually add a visual diff/merge tool in a much earlier version and I missed that.
Ascii is a binary representation. It's just that we've built up a lot of tooling around being to visualize/manipulate that representation. There's no reason that similar tooling couldn't arise for other binary representations
I'm not really sure what your point is. The point is ASCII/UTF-8 are a binary representation that is easily parsed by humans, which is why we use it for writing code. Sure, if you want, dump both files with xxd and do a diff on that instead.
There's been ways to diff binary files forever. Doesn't mean it is a great idea to store source code in that manner though. With UE4 you're not really supposed to be able to edit the Blueprint "code" outside the UE4 Editor.
See the sibling poster, they did actually add a visual diff/merge tool in a much earlier version and I missed that.