The Chinese did that centuries earlier. What Gutenberg invented was moveable type. Little metal blocks with letters on them that can be arranged in rows and columns to form words. The Chinese printers carved entire pages onto wooden blocks, so they got plenty of copies but each character on every page was still made by hand. They're way older than that.
Interchangeable parts allow mass production of commodity products.
Commodities, despite what you may have heard, are seriously cool. They're great for the economy, because they're cheap and plentiful. The end result of any truly mature market niche is commoditization. The cost of production goes way down, and the full power of capitalism is unleashed as multiple vendors compete to provide a better deal on the same goods and services in order to attract customers. Commodities are the lifeblood of capitalism.