Is it permissible to emigrate for one who finds life difficult in a society dominated by ignorance, backwardness, and oppression?

If the society is Muslim and one is able to call people to Allah and teach them matters of their religion, then one should not emigrate from it, because that is part of advising Muslims. However, if one is unable to benefit them and fears for his religion, self, or honor, then he must emigrate to a country where he is safe. If the motive for emigration is seeking livelihood and a wider scope of living, then there is no harm in that, provided that it does not lead to neglecting rights and duties, and that the country one moves to does not pose a danger to his religion or self.