Versions preserve alternatives and history. The current version tells every other view of the project which revision is canonical at this moment.
Without a current version, downstream work is ambiguous
The continuous manuscript, analytics, preview and export all need one revision to use. If a chapter has “Original”, “Editor pass” and “Shorter opening”, the system cannot assemble one book until one becomes the active answer.
Current does not mean final
It is simply the revision the project should behave as if it contains today. Tomorrow another version can become current without deleting the previous one.
This separates history from truth
You can preserve several valid alternatives while still having one predictable manuscript. That is what lets versioning stay useful instead of turning every view into a “which draft?” dialog.
Why text versions? · Why compare versions? · Why lock a version?