The 'numbers' are now 123.45.
123.45 has been the unofficial "gossip" frequency for 30 years or more. We had another unofficial frequency for aerobatic training as well.
119.1 used to be the accepted default airport frequency until CASA needed to re-organise to give the appearance of progress, so it became 126.7
The more things change, the more they stay the same.
And by the way, frequency congestion never seemed to be a problem in the 70's & 80's when there was a) more GA traffic and b) we were all on full reporting with calls at every waypoint and c) we got full flight service on area frequency, with weather, etc on request.