Many critics of Buddhism, like Christianity, will point to its idealism and history, and I think applying dialectical materialism to the question is illuminating. The Buddha did grasp truth and enlightenment is a real thing, but the Buddha existed in a historical context where he had to appeal to Hindus and people in power wanted to gain from the teachings. While human society had to continue reproducing itself, only a small amount of surplus was available to enable people to seek the path. Those who accumulated the surplus became or funded monks, who gave treats of small pieces of semi true knowledge to keep the toiling masses happy (opium so to speak). Once socialism is established I pray unnecessary superstitions and beliefs will fall away as it is made materially accessible (once material needs are covered with minimal time). As humans suffer less materially and society lends towards good karma, may the bodhisattva vow come to fruition.