Doc Writer's Guide on version separation unclear

On the Documentation Writer's Guide page, there's a paragraph that makes no sense to me. Am I misunderstanding something here, or should this be re-written?

Version separation: It's generally better to have one page for all Drupal versions, rather than separate pages. Separate version pages are hard to maintain: when an issue is updated on the page for one version, it's often neglected on the pages for others. Separate handbooks for each version are impractical due to the amount of work; a single set of handbooks is difficult to maintain.

Which way should the Version Separation topic lean? Is it good or bad to have a single set of handbooks?
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Senpai