as long as there is a need to clothe oneself, the fashion designer will exist. The desire for humans to fashion themselves to show their tribe, feel "pretty" or express themselves is part of the human creative spirit.
Discussion
Of course, I'm just looking at the cases where a person doesn't have the discretionary capital, whether money or time, to focus on looking pretty or handsome or well dressed because sustenance does not demand that.
Like, look at those survival challenge reality TV shows. I think one of them is called "Alone". They don't have time to make clothing. They are too busy trying to scrounge up enough food to survive for just 30 days alone out in the wilderness.
At a certain point, the survival group grows large enough to the point where fashion is no longer simply a matter of temperature regulation and armor from bugs and snakes and thorns and whatnot.
On Maslow's Hierarchy of Needs, I'm not 100% sure where I would locate the fashion industry but it would probably be somewhere in the middle. I definitely wouldn't put it at the bottom with the survival needs because clothing is a survival need that can have both function and fashion. Functional clothing goes on the bottom so loin cloths, parkas, etc.
Fashion clothing would not go on the bottom because suits and glittery dresses restrict the wearer's movement are not conducive to survival. It boggles my mind that people choose to wear a noose around their neck every day.