In the end is the PCB design the bottleneck to create new devices or is it mostly about available components and their price?
There are already millions of vendors all over the world making infinite variations of PCB designs for the same/similar product. You can hire a design shop in China for peanuts to make a variation as well.
Ultimately the bottleneck is the consumer does not care for infinite variations. The vast majority just want a "top rated product" at the lowest price. Which is whatever Amazon sorts their results as or whatever the Jones are buying that they need to keep up with.
The biggest driver of "unique product" (not just the 9 millionth clone product) commercial success is marketing, it is branding, it is finding a unique niche, it is timing, it is existing social & business relationships to drive sales.