Most humans, including you, belong to the 99.9999% of Homo sapiens that are isolated from the much smaller isolated groups left. North Sentinel Island, which is nominally governed by India, is home of one of the very few smaller ones. Its locals number in the few hundreds and have likely been there and rejected outsiders for thousands of years.
There was a big story about them rejecting an outsider a while back.
A Christian missionary tried to visit and bring its modern diseases. The Sentinilese fired warning shots but the missionary kept coming right for them, so they had to put it down.
I can’t really get behind your tendency to refer to humans as “it”, but other than that, you seem to understand the facts clearly enough.