^^^ I understand the point you are making but it's not nearly that simple and your premise regarding the number of vendors is way off.
Also, you fail to distinguish between proprietary products and open mold products. Factories produce to the level of quality designed in by their customer. If it's all about price that's the primary driving force with regards to design and construction as opposed to function and durability. The product will reflect that.
Good wheel building isn't magic. It's about being detail oriented and having the same basic knowledge as other capable builders and being meticulous in that process. Some can consistently pull it off and some can't. That's what makes a good wheel builder.