Couple of gems from your link,
There is scarcely any question that Hsuan Tsang arrived in India at a time when Buddhism was entering into a state of precipitous decline, and by the 13th century Buddhism, as a formal religion, had altogether disappeared from India.
Muslim invasions which had the effect of driving into extinction an already debilitated faith.
I like the euphemism that Buddhism was "absorbed" into Hinduism. That's just a fancy way of saying Buddhists were "reconverted" back into Hinduism.
Also, this particular gem is worth noting:
Hindu nationalists appear to think that many Muslim monuments were once Hindu temples, but partisans of Buddhism are inclined to the view that Hindu temples were often built on the site of Buddhist shrines.