Traditional art and architecture never went away. Some people have continued to follow traditional styles in every form of art, regardless of what the current vogue is. Sometimes people’s estimation of the impact of modernism is very distorted, as when some claim that classical music in the 20th century became all dissonance and ugliness, but if you actually add up composers around the world in the 20th century, you find that most of them were writing traditional tonal music, and modernists were a minority that in many places could hardly get any performances.
Usually organizations that call for a "return to traditional art" are ostensibly simply seeking to boost the visibility of traditional styles. But if you engage with those organizations’ ideologues, it often doesn't take long for the mask to come off, and for the person to admit that he/she wishes for non-traditional art to disappear entirely. That seems very rude to that set of people out there (however small or large) who do enjoy avant-garde or modernist art, and who feel their lives would be poorer without it.