Good points. On the bottleneck hypothesis, a new study came out in 2024 arguing that the 900kya population loss was, if not a statistical artifact, more likely a genetic sweep or genome takeover via adaptive advantage. Whatever might be the truth in this case, it is true that human evolution, especially on the cultural plane, has gone through a bunch of major leaps which have had the effect of one small population eventually dominating the global genetic pool. Basically, a winner-takes-all dynamic. One example would be the Proto Indo-Europeans who have replaced male lineages throughout Europe and beyond. There are other such examples as well, like Neanderthal extinction.