For the past 20 years, there has been a steady migration of telecommunications and computing technology from centralised repositories to widely distributed locations. I'm here to suggest that the real answer is both. The big IBM mainframes were dominant.
Telephone is another centralised technology.
All the local lines go to a central office, with a switch, that ultimately hooks up with all the other switches. The Internet, on the other hand, is mainly distributed. The routers and servers are distributed throughout the system. Cable is both. Our infrastructure is designed to be capable of transmitting centralised as well as distributed data and communications.