The problem is really starting g with a coders mindset that reducing a change to an explicit visual representation of a minimal delta is such a useful thing for everybody. It isn't. For example, for images, an A/B comparison is enough in a lot of cases. There are also no meaningful ways to "merge" changes for a lot of data outside source code, so the insistence that version control can't exist without merging is shortsighted.

Meaningful deltas and meaningful merges are actually a problem set that is totally and utterly disjointed from keeping the underlying change history. Deltas and merges can always be computed independently of the underlying storage format for versioned data. Git could have indicriminately used binary deltas for file storage and would still work the same on every higher layer.

In Git the deltas (or diffs) are derived data. They aren't central to what Git is. Natively and conceptually, Git works with repository snapshots.