Imagine there was a society in which blue eyed people are referred to with blee/bler pronouns, and green eyed people are referred to with glee/gler pronouns, and one day someone from that society saw a brown eyed person and had no idea whether to categorise them as blee/bler or glee/gler
If that was the case it would be a much more common feature. There are about 7000 languages in the world and only about a hundred of them have that feature.
But, cultures speaking languages with that feature tend to be much more likely to subjugate other cultures than other cultures are.
So, while if you take a random culture on this planet, it most likely won’t have the he/she distinction in their language. But if you take a random human on this planet, they most likely do have it.