You’re correct about Russia. And the same observation applies to the Indian subcontinent, where I’m from, as well. And, while you’re correct that each place requires a separate analysis, I would guess it applies to most places people leave.
People’s emotions and tribalism often make them romanticize the places they left. They attribute the good things about their society to the people and their culture, but externalize the bad things about their society. That’s usually self-deception.