... I suspect that banking, government, military, and news applications were among the early and prominent ones, possibly with the first world war playing a significant role.
And the adoption curve does suggest wartime acceleration (and a Depression depression). The 50% adoption mark wasn't reached until over 50 years after the telephone's invention.
But somewhere in that history should be clues as to what might lead next-gen comms development.
Generalistic and moderated instance.