The jump from what we now retrospectively call "1G" or original analog cellular to 2G GSM was also similarly huge. We went from things like AMPS analog networks

The jump from what we now retrospectively call "1G" or original analog cellular to 2G GSM was also similarly huge. We went from things like AMPS analog networks that people could listen to with a hacked Oki 900 phone, broadcasting audio calls in the clear as analog radio, to actual GSM.