but it is not in anything close to a growth in many senses.
email will be alive forever as far as I am concerned (just a few months ago a friend of mine managed to send an actual telegram) and probably will be the major player in enterprise communications. but it had sort of reached a plateau in term of functionality.
(on this topic I am actually optimistic for JMAP to help revitalize the field)
Perhaps from the POV of The Valley, but I can assure you that email is alive and well elsewhere.