But IIRC their printing press was not letter-based and as such much less efficient. As for gunpowder, they did not manage to come with the effective firearms and even while they did produce the cannons by the XVI they were clearly behind Europeans in the terms of firearms-based warfare.China had paper, the printing press was invented in Korea and spread to China first, they literally invented gunpowder and cannon.
That’s the problem: they could invent things but not figure out how to use them efficiently.