Was it the advent of the breathalyser which started the non-drinking movement, creating as it did the necessity for at least one person in a group to do everything that the rest of the party did without the benefit of alcohol so that they could be the designated driver? It is now cool not to drink. This newly cool person is a soberista.
The original Soberistas were an online community of women in Britain in 2011, who described themselves as not quite bad enough to join AA but still aware that alcohol was having a detrimental effect on their lives. Their efforts to escape the booze were a more serious undertaking. Now the term has generalised to refer to anyone who extols the virtues of abstaining from alcohol.