The population on Earth is now about 2 billion. Before the "vaxx" it was 2.5 billion. There are people living in the military deep underground bases, I don't know how many, but probably not more than 20 million.
From this 2 billion people about 2 millions are non-humans. 1 million demons and 1 million angels. And a few shape-shifting nature spirits and goblins. Also maybe artificial people/androids.
2 million NHs for 2 billion people means that 1 of 1000 people on Earth is not human. It's not really rare. In a big city with 4 million people there are 4000 NHs (it's not the same everywhere, like LA and DC have more demons than average). You most likely already met a non-human person.
I'm one of the angels on Earth and can see if a person is a human or not.