Comment by triceratops

It wasn't universally due to lack of interest in guns (although in the Qing case, they actually did pull back on the use of firearms due to how poorly both the Ming Dynasty and Dzungar Mongols fared with the matchlock weapons of that era against strategic deployment of Qing horseback archery). India had an enormous arms manufacturing industry that included usage of rocket artillery, Timur absolutely loved using cannons, Ottoman matchlocks were considered the best in the world and even exported to China from the 1500s onward.

It wasn't the lack of arms or interest in arms, it was the lack of development of the sciences which had to flow through the patronage of those in authority. Britain had Newton and Newton co-invented calculus. The invention of the steam engine motivated creation of better machinery and higher precision manufacturing that by the Victorian Era could not be matched by Chinese or Indian workshops. The wealthy gentleman scientist and natural philosopher culture that developed the galvanic pile, the pressure cooker, astronomical telescopes, and the microscope was not something that could develop organically in these Eastern countries due to the political makeup of these empires (largely driven by descendants of nomadic warlords)

That they lost control to some guys that had to travel around entire Africa to get there shows how incompetent and backwards thinking they were. It would be impossible to conquer 100m happy and productive people with just 1000 people even if the 1000 had a bit better guns, especially since the 100m happy and productive people easily could just reproduce the new modern guns.

That India and China were so easy to conquer for Europeans shows the rot in those societies, both in refusing to adopting the superior European technology and by continuing to oppress their own people to such a degree that their people didn't really care much about a foreign power replacing their old tyrants.