Every group has one person who keeps the list
Every recurring group has one. The coach with the spreadsheet of parent phone numbers. The room parent chasing addresses before the class party. The church secretary retyping a directory every January. The person who “does the club’s email list.” Nobody assigns the job. Somebody just ends up holding the list, and then it is theirs for as long as the group exists.
It always breaks the same way. A parent gets a new number and tells the group chat, which the person who keeps the list happens to have muted that week. A member moves and mentions it to one other person, who assumes somebody else will pass it on. Six months later half the entries are wrong, nobody notices until an invitation bounces or a reminder never arrives, and the keeper gets blamed for a job that was never really theirs to do correctly in the first place — because one person cannot be the source of truth for forty other people’s own information.
The scale changes, the bug does not
This is the same failure as any address book, just louder. An individual’s contacts rot because they are holding copies of facts that belong to other people. A group roster rots for the identical reason, except now one person is holding copies of everyone’s facts, on behalf of everyone else who needs them — a youth team, a running club’s Saturday group, a congregation, a neighbourhood association, a small nonprofit’s volunteer list, a five-person business’s client roster. More people depend on the list being right, and exactly one person is positioned to keep it that way. That is not a bigger version of a solvable problem. It is the same structural mistake, scaled up until it actually hurts.
The usual fixes are all a variation on “ask the keeper to try harder.” A pinned message asking everyone to reply with updates. An annual form nobody fills out. A new spreadsheet that starts accurate and is wrong again by the time it matters. None of them touch the actual cause, which is that the keeper is still the one person responsible for information that is not theirs to be responsible for.
Give the list back to the people in it
The fix is the same inversion, just applied to a group instead of a person: nobody should hold a copy of the roster. Everyone should hold their own row in it.
A shared directory works this way. Each member keeps their own details current — the same way they would in their own contacts — and the group simply reads what is already there. When someone changes their number, the directory is right that day, for everyone, without anyone forwarding anything. The keeper’s job does not get easier. It stops existing, because there is no longer a single copy for one person to maintain on behalf of everyone else.
It also stops depending on the keeper personally. A directory can have more than one admin, so the job never rests on whoever happened to start it, and it survives the season the coach steps back or the treasurer hands off the books.
Somebody is always going to start the list — every group needs a first mover. They just should not have to be the one still holding it a year later.