If we use the current definition of species, humans can reproduce with any other human in the planet, therefore we are at this moment the same species. We are probably too promiscuous to expect otherwise.

That's not the definition of species. In many cases different species can reproduce together, e.g. wolves and coyotes. In other cases, species are asexual so clearly there must be some other way of distinguishing them besides sexual compatibility.

The actual definition of species is essentially arbitrary and, when applied to humans and the possibility of different human subspecies or species, the question is essentially political.

It becomes even more obvious when you look into previous proto-human groups like neanderthals, denisovans, etc, as far back as you want; one can ask what counts as a subspecies, what counts as a species, and struggle to apply that in a self-consistent way today between Chinese, neanderthals, Australian aborigines, African pygmies, denisovans, native Americans, etc.

Don't let anyone trick you into thinking there is some clean science answer here - biology is far too messy.

These are political statements and as such they should not be made with the authority of science.

More like the reverse. There's no proof on being separate human species. The rest it's quakey science.

There’s no proof you exist but there’s proof you belong to a group by comparisons.