That niche specie that we let go extinct because of 'naturality' could have evolution advantages over humans that would prove very useful in biological research. They could be especially hardened against cancer for example, but end up being wiped out by disease and famine rather than old age.
Not to mention humanity has a global effect on species population, it would be hubris to assume a species going extinct nowadays is separate from that, even if they have been in a steady decline for quite some time.
Not to mention humanity has a global effect on species population, it would be hubris to assume a species going extinct nowadays is separate from that, even if they have been in a steady decline for quite some time.