Companies only grow when they can contain complexity, and email is the fastest way to produce uncontained complexity. This is because email is built around sending messages from one person to another, or from one group to another; anything in between is an ugly hack.
There’s a good reason most people choose to “Reply All”: all of the recipients of an email have to assume that, until they hear something about it, whatever the email says must be done still must be done. If you’ve ever replied directly to the sender of an email that was sent to ten people, you’ve gotten one of two responses: either ten minutes later you’re “Reply All”‘d on another email that makes yours redundant. At one minute per email times ten recipients, it’s easy to see how a simple task can take an hour or more total—and that’s ignoring the cost of disruptions.
I have a simple solution: “Reply All” should not allow you to compose an email reply; it should send a default answer like “It’s being taken care of.” To recipients who need to know more, you can elaborate; to everyone else, well, it’s being taken care of.
(In the meantime, you can start replying-all with that line. Hopefully it will catch on.)