[jkaving]

As others have commented there are lots of costs and logistical complications involved in a traditional photo shoot. You need to have all the garments of the outfit, the model, the photographer and all support staff in the same place at the same time.

Replacing this with all digital models and clothes would be a big cost reduction.

However, it is still relatively hard to render photo-realistic faces and there's still a long way until all clothes are available as 3D models with realistic simulation of fabrics etc.

But there are already solutions being used today that achieve some of the benefits without using completely generated content.

Looklet[1] provides a system where each garment is shot individually on a mannequin. This is done by a couple of operators in a custom studio, typically placed in a warehouse or similar where samples are received. The images are then combined with other garment images and previously shot images of models to produce photo-realistic catalog images without the need for a traditional photo shoot. The web page has sample images and a list of retailers using this technology.

Take a look at e.g. Saks Off 5th's[2] catalog and see if you can spot the images that have been produced in this way.

[1] https://www.looklet.com

[2] https://www.saksoff5th.com/c/women/apparel