I realized, I don't know many cases of Spanish or Chinese people not learning the language.

My hypothesis: I understand russian and register cases like this easily. Otoh, I don't understand Chinese, so the ones with whom I have ever had any communication, are the ones who learned any of the languages I understand. Similar story with Spanish, my level is ~A2, so there's bias here too, although slightly less prominent.

Do you understand russian?

it's a thing. there are russians that think that they have superior culture and learning some other barbaric language is beneath them.

so they either don't learn native language of the country where they live or learn it to bare minimum