If you are going to have strict dress codes, then runway shows inside the clubs make sense. Aquilon had the strictest dress code and they hosted the most fashion shows. This then branched out to art and performance artist in the most current nightclubs of the day.
These types of events continued even after Club Kids took over the clubs and shattered all fashion norms. Still no tennis shoes allowed though.
An unintended consequence of all these shows was leaving the "runway" up at all times. This ushered in elevated dance. Soon after there were boxes to dance on everywhere. Metropolis even had a elevated strip above their main bar.