The problem with ever-smaller transistors isn't actually a lack of ideas. Optical is promising! 2.5D FinFET is already in production. Gate-all-around transistor

The problem with ever-smaller transistors isn't actually a lack of ideas. Optical is promising! 2.5D FinFET is already in production. Gate-all-around transistors are past the research stage. All of these new technologies are a drastic change to what semiconductor fabs are used to manufacturing. That means new tools, new training, new testing processes, and an unproven economic model. The problem with having too many choices is that companies must choose, and invest heavily in one option. If that fails to scale up to industrial capacity, it could ruin the company. I like optical because it's resistant to EMP, but that might just be my taste in films like the Matrix.