Reviewers should not have to read a 60 page procedure twice to find three changes. A good version comparison shows which steps were added, removed or reworded, and ideally the reason for each change sits right next to it, whether that came from an MOC, an incident or a regulatory update.
This is much easier when procedures are stored as individual steps rather than whole documents, since the comparison happens step by step instead of trying to diff two PDFs. It is one of the practical benefits of moving off paper, and it is also how Interface carries an MOC through to the procedures it affects, so the reviewer sees the change and where it came from in one place.