When you are running a daily stand-up meeting and need to cite Sutherland’s definition of a "Sprint Goal," you need search functionality. EPUBs allow full-text search. You can type "technical debt" or "Scrum Master role" and find the exact passage in seconds.

Detailed long-term plans (Waterfall) fail because they can't adapt to change. The Origins of Scrum

A period of one month or less during which a "Done", useable, and potentially releasable product increment is created.

Scrum is about iterative delivery. An EPUB is inherently agile. Unlike a bulky hardcover or even a PDF, an EPUB reflows text to fit any screen—phone, e-ink reader (Kindle, Kobo), tablet, or laptop. You can read a chapter during a daily commute or a Sprint Retrospective. You can highlight the retrospective questions and sync them across devices.