some people like to list birth, marriage and death dates at the top, and then do a full narrative bio, which of course would need the dates being repeated. When you are looking at a profile, searching to find out if this is the right one for instance, and already know certain facts about who you are looking for, like died before x date, then you can tell at a glance if the profile is likely to be the right one, if death date listed is after your date.