The rsync example confuses me a little bit. If you add a single bit to the front, then all the bytes are shifted into different blocks and nearly none will hash

The rsync example confuses me a little bit. If you add a single bit to the front, then all the bytes are shifted into different blocks and nearly none will hash to match. But if you add a single bit, rsync still performs well. Can someone explain why that difference from the explanation? The problem also applies to the binary delta. Adding a prefix will shift everything forward causing a diff in everything. Bsdiff solves this with the suffix sorting. But what does rsync do? Or am I just wrong that rsync still works well? In either case, I think the offset problem makes for a more interesting motivating example for bsdiff.