While everyone is more likely to associate cropped tops to the era of 90's they got their fame in 80's actually as an aerobic garment, but they had their beginnings even earlier, being a part of the dress ensemble. And then in 70's a male sport wear. I myself found a need in them when I decided to do Velvet skirts.
When you wear a high waisted skirt with any shirt or top (apart of body tops), it will make you look bulky and it will be coming out all the time, and it's even worse with silk based velvet fabrics. Having quite a curvy body type, I always had trouble with tucking in shirts and look clean and chic at the same time, so cropped tops where a perfect answer.
So now we have few types in our arsenal of separates, all called by the name of the dresses they were coming from. Gemma top would be with ¾ zipped sleeves and a turtle neck, Serene is the one with full zipped sleeve with bateau neck line and a semi open back.