Material science just wasn't there. There WERE compound bows, but only in the sense that the bows were made of compound laminates composed of horn, glues, and wood. Mongols got really good at this and could produce very small bows with ridiculously high draw weights (150-200lbs) for their horse archers. What they couldn't do is get a string small enough to work through pulleys like modern compounds. That required modern synthetic fibers that ancient tech just had no equivalent.
Material science just wasn't there. There WERE compound bows, but only in the sense that the bows were made of compound laminates composed of horn, glues, and wood. Mongols got really good at this and could produce very small bows with ridiculously high draw weights (150-200lbs) for their horse archers. What they couldn't do is get a string small enough to work through pulleys like modern compounds. That required modern synthetic fibers that ancient tech just had no equivalent.
Makes sense, the material science for the string fibres wasn't there. Thank you for providing that context and information.