The hard things start below 28nm. Before that you can get away with more traditional optics and optical litho. I fully expect there to be domestic chinese fab equipment companies competing head on with Japanese and American suppliers in processes larger than 28nm. But 5nm has taken more than a decade of R&D and is likely not easily copied.

I'd rather dream about garage scale processes with "green" less poisonous chemicals for artisanal IC production.