Do I need a headrest on a premium ergonomic chair?

Reviewers are split. Many Aeron owners on r/hermanmiller report the seat geometry encourages upright posture and a headrest is unnecessary; others working long video-call days find it essential. Chairs like the GABRYLLY ship with one integrated, while Aeron requires an aftermarket attachment that some specialist reviewers warn alters the chair's intended recline geometry.