My daughter has made at least 10 dresses before graduating from high school. She's now progressed into a textiles program at our university. My step-sister made very elaborate dresses for her daughter throughout school as well.
Sewing/dressmaking is a lot like woodworking. Being able to visualize things well in 3D is an asset, but also having good tools helps as well.
How many people do you know that could turn raw fabric into a dress? I have can do the simplest repairs and even used a sewing machine a few times but that’s not particularly useful to a garment factory.