the reason why 'fallout' is so 'popular' in Russia: It's not really Fallout as a franchise but rather the story of a world that has been destroyed. The one without any sense of direction or substantive replacement for the things that are gone now.
As I see it, it's mostly an unconscious feeling that has to do with USSR's dissolution and Perestroika. 'Russian fallout' is usually a setting soaked in Soviet nostalgia and the signifier of the era past. Usually, nobody is rebuilding anything in it. People are kinda caught in the perpetual state of trance, reliving the realities of the time long gone (agitprop, social realism, the elements of everyday life).
Psychologically, it's a much deeper topic than the western postapoc. For Russia, apocalypse was very much real, and they're still getting over it. It's too early to let the history go and move on. Until then, people are gonna cherish these ruins, an epoch done and gone. While Fallout is a trauma gotten from a threat of nuclear annihilation (hence Fallout's more rational and detached approach), things like ATOM or You Are Empty are the result of a very real trauma, the annihilation of the Soviet world. And since it was not very 'tangible' an annihilation (in the sense that the cultural death is not as tangible as the one caused by nuclear explosions), the consequences are more rooted in culture, art, and the psychology of people that are shaped by said art.