Considering the fact that we interbred with H. neanderthalensis and H. denisova (and still carry the residual DNA to prove it), I think it's pretty well proven that considering only H. sapiens to be "human" is overly narrow.

Personally, I would argue that anything within the Homo genus is human by definition (that's what the word means!), and that anything non-human belongs in a genus like Australopithecus or Paranthropus instead.

Nope. There are modern humans (homo sapiens) and archaic humans (extinct homo species).

https://en.wikipedia.org/wiki/Archaic_humans

That's not entirely accurate anymore.

Yet mounting evidence from fossil and archaeological discoveries, as well as DNA analyses, has experts increasingly rethinking that scenario. It now looks as though H. sapiens originated far earlier than previously thought, possibly in locations across Africa instead of a single region, and that some of its distinguishing traits—including aspects of the brain—evolved piecemeal. Moreover, it has become abundantly clear that H. sapiens actually did mingle with the other human species it encountered and that interbreeding with them may have been a crucial factor in our success.

https://www.scientificamerican.com/article/why-is-homo-sapiens-the-sole-surviving-member-of-the-human-family/