I think this is yet another example of human bias. We want these clear and precise categories, but not everything has clear and precise boundaries. Sometimes its a spectrum. Humankind may be a spectrum. We can certainly see stark differences when we look points on the spectrum that are well separated, but that doesn’t change the fact that there may be a fine gradation between other points.
Are we saying that there was a generation with no language, no burial rights, no sapience, and no sentience, and that the very next generation there was a population of humans who had all of those things in abundance? I highly doubt it. If we look at our closest primate cousins can we say that they don’t have any language or any inkling of sentience or sapience? There’s lots of evidence that even chimps may have rudimentary language. Are they human?
I don’t think we should look at arbitrary boundaries and a lack of a consensus as a failing of science or those trying to define those categories. Instead, we should realize that we are trying to force nature into ill fitting boxes simply because of human preferences.
So how do you view the contrast between the genomes of H. neanderthalensis and ancient H. sapiens? From what I have read (which may be outdated), H. sapiens and H. neanderthalensis were separate species with only limited interbreeding, and it is backed by the differences in their genomes. This would at least be a genetic definition for H. sapiens, but it may not address the larger questions of whether earlier species were human in the philosophical sense.