Anthropologist speaking: Most hominids didn't "die out", they just interbred with homo sapiens to the point where their genes became marginalized. In fact, any person of non-African ethnicity has 1-4% Neanderthal DNA (which means Africans are actually the "purist race", take that 19th century!). Homo Sapien's main claim to success is that it was able to perpetuate and evolve cultural tradition, so every successive generation was able to make better spear heads, fire-starting equipment, etc. To contrast, a previous group of hominids (whose name escapes me right now) were insanely successful across Africa and Eurasia with their own spearheads, but they lacked the ability to socialize and improve opun design, and thus were out-competed by Homo Erectus, Homo Neanderthalis, and eventually Homo Sapiens.