It’s not a technical limitation, at least it wasn’t at the time. German Friedhelm Hillebrand figured that’s all you’d need.

The year was 1985 and the source of the 160 character limitation was rather unusual: Hillebrand just typed (on a typewriter no less) random sentences and questions. According to the LA Times, those short missives never exceeded 160 characters.

This was a very powerful man. One year later, as chairman of the group that established the GSM cellular protocol, he ordered the protocol include Short Messaging Service, and 160 character SMS text messaging was born.