By 1850, Britain controlled the coast of India, Spain controlled the Philippines, and the Netherlands controlled Indonesia. Where was China? Japan was a small power, very poor and isolated, so it couldn’t have done much then. But China was a state of over three hundred million people, it had an economy larger than all of Europe, and, had its government the will, it could have easily ousted the Europeans from India, Indonesia, and the Philippines in the centuries before 1800.
Much for the same reasons European powers didn’t conquer each other. Chinese military technology was too its neighbors for China to be able to have done so if it tried. Plus, if China conquered India, it would not have had the same type of gains from trade, tribute, and specialization Britain had, as China, like India and unlike Britain, was very rural and abundant in goods India and Southeast Asia produced. For Britain, the marginal benefit of more tea, clove, and rice imports was high. This was even true for more agricultural countries like Spain and Portugal. For China, it was very low, indeed. India didn’t have much to offer China, but it had much to offer to the West.
If the the Philippines, Indonesia, and India had substantial silver reserves, the situation might have ended up much different, with China having a much greater incentive to conquer them. Throughout the 18th century, China was a large net importer of silver, and had constant problems with low nominal GDP.