1) Immigration is hard. Particularly when you are not from a well-developed country with a powerful passport. You will live on a borrowed time, where the host country will invent reasons to deport you (to Russia, of course, where you most probably will be jailed in no time). I live in Switzerland for 18 years, and still on a temporary residence permit, as the Swiss government invents more and more creative laws and rules to deny me a permanent residence, not to mention citizenship, which is a pipe dream at this point.

2) Leaving your parents and elder relatives might not be something many people are ready for. In Russia, there is a strong notion that children are supposed to support their parents in the old age.

3) One misadventure with the Russian law (and many people from Russian opposition have a lot of them for their protests), and you can’t go out. You will be stopped at the border. The ability to exit the country is a privilege in Russia; not yet at the level it used to be in the USSR, but a privilege nonetheless.

4) Some heroic people think that they have to stay and fight, instead of quitting. It might be near impossible, but they have a reason.

Etc, etc. Those who could move out are really lucky. I am lucky, too.